Publications

1. B. Liu, H. Xie, Y. Liu, C. Wang, S. Wang, Y. Zhao, J. Liu, D. Niu, H. Huang & Y. Gao. Electronic structure and spin polarization of Co/black phosphorus interface. Journal of Magnetism and Magnetic Materials 499, 166297 (2020).

2. C. Wang, J. Zhang, J. Duan, L. Gong, J. Wu, L. Jiang, C. Zhou, H. Xie, Y. Gao & H. He. All-inorganic, hole-transporting-layer-free, carbon-based CsPbIBr2 planar perovskite solar cells by a two-step temperature-control annealing process. Materials Science in Semiconductor Processing 108, 104870 (2020).

3. C. Wang, J. Zhang, L. Jiang, L. Gong, H. Xie, Y. Gao, H. He, Z. Fang, J. Fan & Z. Chao. All-inorganic, hole-transporting-layer-free, carbon-based CsPbIBr2 planar solar cells with ZnO as electron-transporting materials. Journal of Alloys and Compounds 817, 152768 (2020).

4. W.-Q. Wu, P. N. Rudd, Z. Ni, C. H. Van Brackle, H. Wei, Q. Wang, B. R. Ecker, Y. Gao & J. Huang. Reducing Surface Halide Deficiency for Efficient and Stable Iodide-Based Perovskite Solar Cells. Journal of the American Chemical Society (2020).

5. H. Xie, D. Niu, Y. Zhao, S. Wang, B. Liu, Y. Liu, H. Huang, P. Wang, D. Wu & Y. Gao. Photoemission studies of C8-BTBT/La0. 67Sr0. 33MnO3 interface. Synthetic Metals 260, 116261 (2020).

6. W. Alquraishi, Y. Fu, W. Qiu, J. Wang, Y. Chen, L.-A. Kong, J. Sun & Y. Gao. Hybrid optoelectronic synaptic functionality realized with ion gel-modulated In2O3 phototransistors. Organic Electronics 71, 72-78 (2019).

7. Y. Chen, W. Qiu, X. Wang, W. Liu, J. Wang, G. Dai, Y. Yuan, Y. Gao & J. Sun. Solar-blind SnO2 nanowire photo-synapses for associative learning and coincidence detection. Nano Energy 62, 393-400 (2019).

8. Y. Chen, J. Sun, W. Qiu, X. Wang, W. Liu, Y. Huang, G. Dai, J. Yang & Y. Gao. Deep-ultraviolet SnO 2 nanowire phototransistors with an ultrahigh responsivity. Applied Physics A 125, 691 (2019).

9. B. He, G. Tian, J. Gou, B. Liu, K. Shen, Q. Tian, Z. Yu, F. Song, H. Xie & Y. Gao. Structural and electronic properties of atomically thin Bismuth on Au (111). Surface Science 679, 147-153 (2019).

10. K. Huang, H. Li, C. Zhang, Y. Gao, T. Liu, J. Zhang, Y. Gao, Y. Peng, L. Ding & J. Yang. Highly Efficient Perovskite Solar Cells Processed Under Ambient Conditions Using In Situ Substrate‐Heating‐Assisted Deposition. Solar RRL 3, 1800318 (2019).

11. K. Huang, Y. Peng, Y. Gao, J. Shi, H. Li, X. Mo, H. Huang, Y. Gao, L. Ding & J. Yang. High‐Performance Flexible Perovskite Solar Cells via Precise Control of Electron Transport Layer. Advanced Energy Materials (2019).

12. J. Jiang, W. Hu, D. Xie, J. Yang, J. He, Y. Gao & Q. Wan. 2D electric-double-layer phototransistor for photoelectronic and spatiotemporal hybrid neuromorphic integration. Nanoscale 11, 1360-1369 (2019).

13. L. Li, C. Wang, C. Wang, S. Tong, Y. Zhao, H. Xia, J. Shi, J. Shen, H. Xie, X. Liu, D. Niu, J. Yang, H. Huang, S. Xiao, J. He & Y. Gao. Interfacial electronic structures of MoOx/mixed perovskite photodetector. Organic Electronics 65, 162-169 (2019).

14. N. Li, S. Tao, Y. Chen, X. Niu, C. K. Onwudinanti, C. Hu, Z. Qiu, Z. Xu, G. Zheng, L. Wang, Y. Zhang, L. Li, H. Liu, Y. Lun, J. Hong, X. Wang, Y. Liu, H. Xie, Y. Gao, Y. Bai, S. Yang, G. Brocks, Q. Chen & H. Zhou Cation and anion immobilization through chemical bonding enhancement with fluorides for stable halide perovskite solar cells. Nature energy 4, 408 (2019).

15. Y. Li, C. Liao, K. Tang, N. Zhang, W. Qi, H. Xie, J. He, K. Yin, Y. Gao & C. Wang. Cobalt hydroxide-black phosphorus nanosheets: A superior electrocatalyst for electrochemical oxygen evolution. Electrochimica Acta 297, 40-45 (2019).

16. Y. Li, W. Pei, J. He, K. Liu, W. Qi, X. Gao, S. Zhou, H. Xie, K. Yin & Y. Gao. Hybrids of PtRu Nanoclusters and Black Phosphorus Nanosheets for Highly Efficient Alkaline Hydrogen Evolution Reaction. ACS Catalysis (2019).

17. B. Liu, H. Xie, D. Niu, S. Wang, Y. Zhao, Y. Liu, L. Lyu & Y. Gao. Effect of interfacial interaction on spin polarization at organic-cobalt interface. Organic Electronics, 105567 (2019).

18. G. Liu, B. Yang, H. Chen, Y. Zhao, H. Xie, Y. Yuan, Y. Gao & C. Zhou. In situ surface modification of TiO2 by CaTiO3 to improve the UV stability and power conversion efficiency of perovskite solar cells. Applied Physics Letters 115, 213501 (2019).

19. Y. Liu, C. Xie, W. Tan, X. Liu, Y. Yuan, Q. Xie, Y. Li & Y. Gao. Analysis of light-induced degradation in inverted perovskite solar cells under short-circuited conditions. Organic Electronics 71, 123-130 (2019).

20. Y. Liu, H. Zai, H. Xie, B. Liu, S. Wang, Y. Zhao, D. Niu, H. Huang, Q. Chen & Y. Gao. Effects of CsPbBr3 nanocrystals concentration on electronic structure and surface composition of perovskite films. Organic Electronics 73, 327-331 (2019).

21. C. Qian, S. Oh, Y. Choi, J.-H. Kim, J. Sun, H. Huang, J. Yang, Y. Gao, J.-H. Park & J. H. Cho. Solar-stimulated optoelectronic synapse based on organic heterojunction with linearly potentiated synaptic weight for neuromorphic computing. Nano Energy 66, 104095 (2019).

22. Q. Tian, B. He, Y. Zhao, S. Wang, J. Xiao, F. Song, Y. Wang, Y. Lu, H. Xie, H. Huang & Y. Gao. Electronic structure evolution at DBBA/Au (111) interface W/O Bismuth insertion layer. Synthetic Metals 251, 24-29 (2019).

23. S. Tong, C. Gong, C. Zhang, G. Liu, D. Zhang, C. Zhou, J. Sun, S. Xiao, J. He & Y. Gao. Fully-printed, flexible cesium-doped triple cation perovskite photodetector. Applied Materials Today 15, 389-397 (2019).

24. C. Wang, D. Niu, Y. Zhao, S. Wang, C. Qian, H. Huang, H. Xie & Y. Gao. Interface Energy-Level Alignment between Black Phosphorus and F16CuPc Molecular Films. The Journal of Physical Chemistry C 123, 10443-10450 (2019).

25. C. Wang, J. Zhang, L. Jiang, L. Gong, H. Xie, Y. Gao, H. He, Z. Fang, J. Fan & Z. Chao. All-inorganic, hole-transporting-layer-free, carbon-based CsPbIBr2 planar solar cells with ZnO as electron-transporting materials. Journal of Alloys and Compounds, 152768 (2019).

26. S. Wang, L. Lyu, D. Niu, L. Zhang, H. Huang & Y. Gao. Breaking down and reconstruction of islands during the film growth of CuPc on HOPG. Applied Physics Letters 114, 241602 (2019).

27. D. Wu, J. Shi, X. Zheng, J. Liu, W. Dou, Y. Gao, X. Yuan, F. Ouyang & H. Huang. CVD Grown MoS2 Nanoribbons on MoS2 Covered Sapphire (0001) Without Catalysts (Phys. Status Solidi RRL 7/2019). physica status solidi (RRL)–Rapid Research Letters 13 (2019).

28. J. Xiao, J. Liu, K. Sun, Y. Zhao, Z. Shao, X. Liu, Y. Yuan, Y. Li, H. Xie, F. Song, Y. Gao & H. Huang. PbI2–MoS2 Heterojunction: van der Waals Epitaxial Growth and Energy Band Alignment. The journal of physical chemistry letters 10, 4203-4208 (2019).

29. J. Yan, Y. Chen, X. Wang, Y. Fu, J. Wang, J. Sun, G. Dai, S. Tao & Y. Gao. High-performance solar-blind SnO 2 nanowire photodetectors assembled using optical tweezers. Nanoscale 11, 2162-2169 (2019).

30. J. Yan, S. Lin, X. Qiu, H. Chen, K. Li, Y. Yuan, M. Long, B. Yang, Y. Gao & C. Zhou. Accelerated hole-extraction in carbon-electrode based planar perovskite solar cells by moisture-assisted post-annealing. Applied Physics Letters 114, 103503 (2019).

31. B. Zeng, M. Long, Y. Dong, J. Xiao, S. Zhang, Y. Yi & Y. Gao. Stress-sign-tunable Poisson’s ratio in monolayer blue phosphorus oxide. Journal of Physics: Condensed Matter 31, 295702 (2019).

32. H. Zhang, Z. Zhang, C. Ma, Y. Liu, H. Xie, S. Luo, Y. Yuan, Y. Gao, Y. Zhang & W. Ming. Low-temperature synthesis of all-inorganic perovskite nanocrystals for UV-photodetectors. Journal of Materials Chemistry C 7, 5488-5496 (2019).

33. X. Zheng, Y. Wei, J. Liu, S. Wang, J. Shi, H. Yang, G. Peng, C. Deng, W. Luo, Y. Zhao, Y. Li, K.L. Sun, W. Wan, H. Xie, Y. Gao, X. Zhang & H. Huang. Homogeneous PN Junction Diode by Selective Doping Few layer MoSe2 Using Ultraviolet Ozone for High-Performance Photovoltaic Devices. Nanoscale (2019).

34. B. Zeng, M. Long, Y. Dong, J. Xiao, S. Zhang, Y. Yi & Y. Gao. Sign-tunable Poisson's Ratio in Blue Phosphorus Oxide. arXiv preprint arXiv:1808.01733 (2018).

35. D. Xie, J. Jiang, W. Hu, Y. He, J. Yang, J. He, Y. Gao & Q. Wan. Coplanar multigate MoS2 electric-double-layer transistors for neuromorphic visual recognition. ACS applied materials & interfaces 10, 25943-25948 (2018).

36. X. Xiao, C. Bao, Y. Fang, J. Dai, B. R. Ecker, C. Wang, Y. Lin, S. Tang, Y. Liu, Y. Deng, X. Zheng, Y. Gao, X. Zeng & J. Huang. Argon Plasma Treatment to Tune Perovskite Surface Composition for High Efficiency Solar Cells and Fast Photodetectors. Advanced Materials 30, 1705176 (2018).

37. H. Xia, S. Tong, C. Zhang, C. Wang, J. Sun, J. He, J. Zhang, Y. Gao & J. Yang. Flexible and air-stable perovskite network photodetectors based on CH3NH3PbI3/C8BTBT bulk heterojunction. Applied Physics Letters 112, 233301 (2018).

38. D. Wu, Y. Yang, P. Zhu, X. Zheng, X. Chen, J. Shi, F. Song, X. Gao, X. Zhang, F. Ouyang, X. Xiong, Y. Gao & H. Huang. Epitaxial Growth of Highly Oriented Metallic MoO2@ MoS2 Nanorods on C-sapphire. The Journal of Physical Chemistry C 122, 1860-1866 (2018).

39. X. Wei, S. Wang, C. Wang, M. Zhu, Y. Zhao, H. Xie, D. Niu & Y. Gao. Electronic Structures and Nanofilm Growth of 2, 7-Dioctyl [1] Benzothieno [3, 2-b] Benzothiophene on Black Phosphorus. Journal of nanoscience and nanotechnology 18, 4332-4336 (2018).

40. J. Wang, Y. Chen, L.-A. Kong, Y. Fu, Y. Gao & J. Sun. Deep-ultraviolet-triggered neuromorphic functions in In-Zn-O phototransistors. Applied Physics Letters 113, 151101 (2018).

41. C. Wang, C. Zhang, S. Wang, G. Liu, H. Xia, S. Tong, J. He, D. Niu, C. Zhou, K. Ding, Y. Gao & J. Yang. Low‐Temperature Processed, Efficient, and Highly Reproducible Cesium‐Doped Triple Cation Perovskite Planar Heterojunction Solar Cells. Solar RRL 2, 1700209 (2018).

42. C. Wang, D. Niu, S. Wang, Y. Zhao, W. Tan, L. Li, H. Huang, H. Xie, Y. Deng & Y. Gao. Energy Level Evolution and Oxygen Exposure of Fullerene/Black Phosphorus Interface. The journal of physical chemistry letters 9, 5254-5261 (2018).

43. C. Wang, Y. Li, C. Zhang, L. Shi, S. Tong, B. Guo, J. Zhang, J. He, Y. Gao & C. Su. Enhancing the performance of planar heterojunction perovskite solar cells using stable semiquinone and amine radical modified hole transport layer. Journal of Power Sources 390, 134-141 (2018).

44. C. Wang & Y. Gao. Stability of Perovskites at the Surface Analytic Level. The journal of physical chemistry letters 9, 4657-4666 (2018).

45. C. Wang, B. R. Ecker, H. Wei, J. Huang & Y. Gao. Environmental Surface Stability of the MAPbBr3 Single Crystal. The Journal of Physical Chemistry C 122, 3513-3522 (2018).

46. F. Wan, X. Qiu, H. Chen, Y. Liu, H. Xie, J. Shi, H. Huang, Y. Yuan, Y. Gao & C. Zhou. Accelerated electron extraction and improved UV stability of TiO2 based perovskite solar cells by SnO2 based surface passivation. Organic Electronics 59, 184-189 (2018).

47. S. Tong, J. Yuan, C. Zhang, C. Wang, B. Liu, J. Shen, H. Xia, Y. Zou, H. Xie, J. Sun, S. Xiao, J. He, Y. Gao & J. Yang. Large-scale roll-to-roll printed, flexible and stable organic bulk heterojunction photodetector. npj Flexible Electronics 2, 7 (2018).

48. W. Tan, C. Xie, Y. Liu, Y. Zhao, L. Li, X. Liu, Y. Yuan, Y. Li & Y. Gao. Initial photochemical stability in perovskite solar cells based on the Cu electrode and the appropriate charge transport layers. Synthetic Metals 246, 101-107 (2018).

49. J. Shi, D. Wu, X. Zheng, D. Xie, F. Song, X. Zhang, J. Jiang, X. Yuan, Y. Gao & H. Huang. From MoO2@ MoS2 Core–Shell Nanorods to MoS2 Nanobelts. physica status solidi (b) 255, 1800254 (2018).

50. X. Qiu, B. Yang, H. Chen, G. Liu, Y. Liu, Y. Yuan, H. Huang, H. Xie, D. Niu & Y. Gao. Efficient, stable and flexible perovskite solar cells using two-step solution-processed SnO2 layers as electron-transport-material. Organic Electronics 58, 126-132 (2018).

51. H. Liu, B. Yang, H. Chen, K. Li, G. Liu, Y. Yuan, Y. Gao & C. Zhou. Efficient and stable hole-conductor-free mesoscopic perovskite solar cells using SiO2 as blocking layer. Organic Electronics 58, 69-74 (2018).

52. G. Liu, C. Zhou, F. Wan, K. Li, Y. Yuan, Y. Gao, Y. Lu & B. Yang. Dependence of power conversion properties of perovskite solar cells on operating temperature. Applied Physics Letters 113, 113501 (2018).

53. B. Liu, H. Xie, D. Niu, H. Huang, C. Wang, S. Wang, Y. Zhao, Y. Liu & Y. Gao. Interface Electronic Structure between Au and Black Phosphorus. The Journal of Physical Chemistry C 122, 18405-18411 (2018).

54. S. Lin, B. Yang, X. Qiu, J. Yan, J. Shi, Y. Yuan, W. Tan, X. Liu, H. Huang & Y. Gao. Efficient and stable planar hole-transport-material-free perovskite solar cells using low temperature processed SnO 2 as electron transport material. Organic Electronics 53, 235-241 (2018).

55. S. Li, S. Tong, J.-Q. Meng, C. Zhang, C. Zhang, J. Shen, S. Xiao, J. Sun, J. He & Y. Gao. Fast-response and high-responsivity FAxMA (1− x) PbI3 photodetectors fabricated via doctor-blading deposition in ambient condition. Organic Electronics 52, 190-194 (2018).

56. L. Li, S. Tong, Y. Zhao, C. Wang, S. Wang, L. Lyu, Y. Huang, H. Huang, J. Yang, D. Niu & Y. Gao. Interfacial Electronic Structures of Photodetector Based on C8BTBT/Perovskite. ACS applied materials & interfaces 10, 20959–20967 (2018).

57. K. Li, H. Chen, H. Liu, Y. Yuan, Y. Gao, B. Yang & C. Zhou. Dependence of power conversion properties of the hole-conductor-free mesoscopic perovskite solar cells on the thickness of carbon film. Organic Electronics 62, 298-303 (2018).

58. L. Kang, H. Chen, Z.-J. Yang, Y. Yuan, H. Huang, B. Yang, Y. Gao & C. Zhou. Seesaw-like polarized transmission behavior of silver nanowire arrays aligned by off-center spin-coating. Journal of Applied Physics 123, 205110 (2018).

59. Y. Jiang, Y. Ma, Z. Fan, P. Wang, X. Li, Y. Wang, Y. Zhang, J. Shen, G. Wang & Z.-J. Yang, S. Xiao, Y. Gao & J. He. Abnormal nonlinear optical properties of hybrid graphene-TiO 2 nanostructures. Optics letters 43, 523-526 (2018).

60. K. Huang, C. Wang, C. Zhang, S. Tong, H. Li, B. Liu, Y. Gao, Y. Dong, Y. Gao & Y. Peng. Efficient and stable planar heterojunction perovskite solar cells fabricated under ambient conditions with high humidity. Organic Electronics 55, 140-145 (2018).

61. Y. Gao, Y. Dong, K. Huang, C. Zhang, B. Liu, S. Wang, J. Shi, H. Xie, H. Huang & S. Xiao, J. He, Y. Gao, R.A. Hatton & J. Yang. Highly Efficient, Solution-Processed CsPbI2Br Planar Heterojunction Perovskite Solar Cells via Flash Annealing. ACS Photonics 5, 4104-4110 (2018).

62. Y. Fu, L.-a. Kong, Y. Chen, J. Wang, C. Qian, Y. Yuan, J. Sun, Y. Gao & Q. Wan. Flexible Neuromorphic Architectures Based on Self-Supported Multiterminal Organic Transistors. ACS applied materials & interfaces 10, 26443-26450 (2018).

63. B. R. Ecker, C. Wang, H. Wei, Y. Yuan, J. Huang & Y. Gao. Intrinsic Behavior of CH3NH3PbBr3 Single Crystals under Light Illumination. Advanced Materials Interfaces, 1801206 (2018).

64. H. Chen, K. Li, H. Liu, Y. Gao, Y. Yuan, B. Yang & C. Zhou. Dependence of power conversion properties of hole-conductor-free mesoscopic perovskite solar cells on the loading of perovskite crystallites. Organic Electronics 61, 119-124 (2018).

65. M. Zhu, L. Lyu, D. Niu, H. Zhang, Y. Zhang, P. Liu & Y. Gao. Interfacial chemical and electronic structure of cobalt deposition on 2, 7-dioctyl [1] benzothieno [3, 2-b] benzothiophene (C8-BTBT). Applied Surface Science 402, 142-146 (2017).

66. Y. Zhao, X. Liu, L. Lyu, L. Li, W. Tan, S. Wang, C. Wang, D. Niu, H. Xie, H. Huang & Y. Gao. Fullerene (C 60) interlayer modification on the electronic structure and the film growth of 2, 7-diocty [1] benzothieno-[3, 2-b] benzothiophene on SiO 2. Synthetic Metals 229, 1-6 (2017).

67. H. Zai, C. Zhu, H. Xie, Y. Zhao, C. Shi, Z. Chen, X. Ke, M. Sui, C. Chen, J. Hu, Q. Zhang, Y. Gao, H. Zhou, Y. Li, & Q. Chen. Congeneric incorporation of CsPbBr3 nanocrystals in a hybrid perovskite heterojunction for photovoltaic efficiency enhancement. ACS Energy Letters 3, 30-38 (2017).

68. K.-W. Yang, M.-J. Li, X.-J. Zhang, X.-M. Li, Y.-L. Gao & M.-Q. Long. Spin-dependent transport characteristics of nanostructures based on armchair arsenene nanoribbons. Chinese Physics B 26, 098509 (2017).

69. L. Xu, F. Wan, Y. Rong, H. Chen, S. He, X. Xu, G. Liu, H. Han, Y. Yuan, J. Yang, Y. Gao, B. Yang & C. Zhou. Stable monolithic hole-conductor-free perovskite solar cells using TiO2 nanoparticle binding carbon films. Organic Electronics 45, 131-138 (2017).

70. Q. Xie, X. Zheng, D. Wu, X. Chen, J. Shi, X. Han, X. Zhang, G. Peng, Y. Gao & H. Huang. High electrical conductivity of individual epitaxially grown MoO2 nanorods. Applied Physics Letters 111, 093505 (2017).

71. H. Wu, C. Zhang, K. Ding, L. Wang, Y. Gao & J. Yang. Efficient planar heterojunction perovskite solar cells fabricated by in-situ thermal-annealing doctor blading in ambient condition. Organic Electronics 45, 302-307 (2017).

72. Y. W. Wang, S. Liu, B. W. Zeng, H. Huang, J. Xiao, J. B. Li, M. Q. Long, S. Xiao, X. F. Yu & Y. L. Gao. Ultraviolet saturable absorption and ultrafast carrier dynamics in ultrasmall black phosphorus quantum dots. Nanoscale 9, 4683-4690 (2017).

73. S. Wang, D. Niu, L. Lyu, Y. Huang, X. Wei, C. Wang, H. Xie & Y. Gao. Interface electronic structure and morphology of 2, 7-dioctyl [1] benzothieno [3, 2-b] benzothiophene (C8-BTBT) on Au film. Applied Surface Science 416, 696-703 (2017).

74. C. Wang, C. Zhang, S. Tong, H. Xia, L. Wang, H. Xie, Y. Gao & J. Yang. Energy level and thickness control on PEDOT: PSS layer for efficient planar heterojunction perovskite cells. Journal of Physics D: Applied Physics 51, 025110 (2017).

75. C. Wang, C. Zhang, S. Tong, J. Shen, C. Wang, Y. Li, S. Xiao, J. He, J. Zhang & Y. Gao. Air-induced high-quality CH3NH3PbI3 thin film for efficient planar heterojunction perovskite solar cells. The Journal of Physical Chemistry C 121, 6575-6580 (2017).

76. C. Wang, C. Zhang, Y. Huang, S. Tong, H. Wu, J. Zhang, Y. Gao & J. Yang. Degradation behavior of planar heterojunction CH3NH3PbI3 perovskite solar cells. Synthetic Metals 227, 43-51 (2017).

77. C. Wang, D. Niu, H. Xie, B. Liu, S. Wang, M. Zhu & Y. Gao. Electronic structures at the interface between CuPc and black phosphorus. The Journal of chemical physics 147, 064702 (2017).

78. C. Wang, D. Niu, B. Liu, S. Wang, X. Wei, Y. Liu, H. Xie & Y. Gao. Charge Transfer at the PTCDA/Black Phosphorus Interface. The Journal of Physical Chemistry C 121, 18084-18094 (2017).

79. C. Wang, B. R. Ecker, H. Wei, J. Huang, J.-Q. Meng & Y. Gao. Valence band dispersion measurements of perovskite single crystals using angle-resolved photoemission spectroscopy. Physical Chemistry Chemical Physics 19, 5361-5365 (2017).

80. S. Tong, H. Wu, C. Zhang, S. Li, C. Wang, J. Shen, S. Xiao, J. He, J. Yang, J. Sun & Y. Gao. Large-area and high-performance CH3NH3PbI3 perovskite photodetectors fabricated via doctor blading in ambient condition. Organic Electronics 49, 347-354 (2017).

81. S. Tong, J. Sun, C. Wang, Y. Huang, C. Zhang, J. Shen, H. Xie, D. Niu, S. Xiao & Y. Yuan, J. He, J. Yang & Y. Gao. High‐Performance Broadband Perovskite Photodetectors Based on CH3NH3PbI3/C8BTBT Heterojunction. Advanced Electronic Materials 3, 1700058 (2017).

82. G. Tian, Y. Shen, B. He, Z. Yu, F. Song, Y. Lu, P. Wang, Y. Gao & H. Huang. Effects of monolayer Bi on the self-assembly of DBBA on Au (111). Surface Science 665, 89-95 (2017).

83. Y. Shen, G. Tian, H. Huang, Y. He, Q. Xie, F. Song, Y. Lu, P. Wang & Y. Gao. Chiral self-assembly of nonplanar 10, 10′-dibromo-9, 9′-bianthryl molecules on Ag (111). Langmuir 33, 2993-2999 (2017).

84. C. Qian, J. Sun, L.-a. Kong, Y. Fu, Y. Chen, J. Wang, S. Wang, H. Xie, H. Huang, J. Yang & Y. Gao. Multilevel Nonvolatile Organic Photomemory Based on Vanadyl-Phthalocyanine/para-Sexiphenyl Heterojunctions. ACS Photonics 4, 2573-2579 (2017).

85. C. Qian, J. Sun, L. A. Kong, G. Gou, M. Zhu, Y. Yuan, H. Huang, Y. Gao & J. Yang. High‐Performance Organic Heterojunction Phototransistors Based on Highly Ordered Copper Phthalocyanine/para‐Sexiphenyl Thin Films. Advanced Functional Materials 27, 1604933 (2017).

86. C. Qian, L.-a. Kong, J. Yang, Y. Gao & J. Sun. Multi-gate organic neuron transistors for spatiotemporal information processing. Applied Physics Letters 110, 083302 (2017).

87. L. Lyu, D. Niu, H. Xie, Y. Zhao, N. Cao, H. Zhang, Y. Zhang, P. Liu & Y. Gao. The correlations of the electronic structure and film growth of 2, 7-diocty [1] benzothieno [3, 2-b] benzothiophene (C8-BTBT) on SiO 2. Physical Chemistry Chemical Physics 19, 1669-1676 (2017).

88. H. Lv, C. Wang, G. Li, R. Burke, T. D. Krauss, Y. Gao & R. Eisenberg. Semiconductor quantum dot-sensitized rainbow photocathode for effective photoelectrochemical hydrogen generation. Proceedings of the National Academy of Sciences 114, 11297-11302 (2017).

89. P. Liu, B.-c. Yang, G. Liu, R.-s. Wu, C.-j. Zhang, F. Wan, S.-g. Li, J.-l. Yang, Y.-l. Gao & C.-h. Zhou. Improving power conversion efficiency of perovskite solar cells by cooperative LSPR of gold-silver dual nanoparticles. Chinese Physics B 26, 058401 (2017).

90. G. Liu, B. Yang, B. Liu, C. Zhang, S. Xiao, Y. Yuan, H. Xie, D. Niu, J. Yang & Y. Gao. Irreversible light-soaking effect of perovskite solar cells caused by light-induced oxygen vacancies in titanium oxide. Applied Physics Letters 111, 153501 (2017).

91. Y. Li, X. Xu, C. Wang, B. Ecker, J. Yang, J. Huang & Y. Gao. Light-induced degradation of CH3NH3PbI3 hybrid perovskite thin film. The Journal of Physical Chemistry C 121, 3904-3910 (2017).

92. X. Li, R. Liu, H. Xie, Y. Zhang, B. Lyu, P. Wang, J. Wang, Q. Fan, Y. Ma, S. Tao. S. Xiao, X. Yu, Y. Gao & Jun He Tri-phase all-optical switching and broadband nonlinear optical response in Bi 2 Se 3 nanosheets. Optics Express 25, 18346-18354 (2017).

93. S. Li, S. Tong, J. Yang, H. Xia, C. Zhang, C. Zhang, J. Shen, S. Xiao, J. He & Y. Gao. High-performance formamidinium-based perovskite photodetectors fabricated via doctor-blading deposition in ambient condition. Organic Electronics 47, 102-107 (2017).

94. M. Li, D. Zhang, Y. Gao, C. Cao & M. Long. Half-metallicity and spin-polarization transport properties in transition-metal atoms single-edge-terminated zigzag α-graphyne nanoribbons. Organic Electronics 44, 168-175 (2017).

95. L.-a. Kong, J. Sun, C. Qian, C. Wang, J. Yang & Y. Gao. Spatially-correlated neuron transistors with ion-gel gating for brain-inspired applications. Organic Electronics 44, 25-31 (2017).

96. L.-a. Kong, J. Sun, C. Qian, Y. Fu, J. Wang, J. Yang & Y. Gao. Long-term synaptic plasticity simulated in ionic liquid/polymer hybrid electrolyte gated organic transistors. Organic Electronics 47, 126-132 (2017).

97. J. Jiang, J. Guo, X. Wan, Y. Yang, H. Xie, D. Niu, J. Yang, J. He, Y. Gao & Q. Wan. 2D MoS2 Neuromorphic Devices for Brain‐Like Computational Systems. Small 13, 1700933 (2017).

98. S. Hao, B. Yang, J. Yuan & Y. Gao. Substrate induced anomalous electrostatic and photoluminescence propeties of monolayer MoS2 edges. Solid State Communications 249, 1-6 (2017).

99. S. Hao, B. Yang & Y. Gao. Orientation-specific transgranular fracture behavior of CVD-grown monolayer MoS2 single crystal. Applied Physics Letters 110, 153105 (2017).

100. S. Hao, B. Yang & Y. Gao. Chemical vapor deposition growth and characterization of drop‐like MoS2/MoO2 granular films. physica status solidi (b) 254, 1600245 (2017).

101. C. Cao, C. Zhang, J. Yang, J. Sun, S. Pang, H. Wu, R. Wu, Y. Gao & C. Liu. Iodine and chlorine element evolution in CH3NH3PbI3–x Cl x thin films for highly efficient planar heterojunction perovskite solar cells. Chemistry of Materials 28, 2742-2749 (2016).

102. G. Gou, G. Dai, C. Qian, Y. Liu, Y. Fu, Z. Tian, Y. He, L. Kong, J. Yang, J. Sun & Y. Gao. High-performance ultraviolet photodetectors based on CdS/CdS: SnS 2 superlattice nanowires. Nanoscale 8, 14580-14586 (2016).

103. G. Gou, J. Sun, C. Qian, Y. He, L.-a. Kong, Y. Fu, G. Dai, J. Yang & Y. Gao. Artificial synapses based on biopolymer electrolyte-coupled SnO 2 nanowire transistors. Journal of Materials Chemistry C 4, 11110-11117 (2016).

104. S. Hao, B. Yang & Y. Gao. Unravelling merging behaviors and electrostatic properties of CVD-grown monolayer MoS2 domains. The Journal of chemical physics 145, 084704 (2016).

105. S. Hao, B. Yang & Y. Gao. Controllable growth and characterizations of hybrid spiral-like atomically thin molybdenum disulfide. Physica E: Low-dimensional Systems and Nanostructures 84, 378-383 (2016).

106. S. Hao, B. Yang & Y. Gao. Quenching induced fracture behaviors of CVD-grown polycrystalline molybdenum disulfide films. RSC Advances 6, 59816-59822 (2016).

107. S. Hao, B. Yang & Y. Gao. Controllable growth and electrostatic properties of Bernal stacked bilayer MoS2. Journal of Applied Physics 120, 124310 (2016).

108. S. Hao, B. Yang & Y. Gao. Fracture‐induced nanoscrolls from CVD‐grown monolayer molybdenum disulfide. physica status solidi (RRL)-Rapid Research Letters 10, 549-553 (2016).

109. Y. He, J. Sun, C. Qian, L.-a. Kong, J. Jiang, J. Yang, H. Li & Y. Gao. Solution-processed natural gelatin was used as a gate dielectric for the fabrication of oxide field-effect transistors. Organic Electronics 38, 357-361 (2016).

110. A. C. Hinckley, C. Wang, R. Pfattner, D. Kong, Y. Zhou, B. Ecker, Y. Gao & Z. Bao. Investigation of a Solution-Processable, Nonspecific Surface Modifier for Low Cost, High Work Function Electrodes. ACS applied materials & interfaces 8, 19658-19664 (2016).

111. Q. Hu, H. Wu, J. Sun, D. Yan, Y. Gao & J. Yang. Large-area perovskite nanowire arrays fabricated by large-scale roll-to-roll micro-gravure printing and doctor blading. Nanoscale 8, 5350-5357 (2016).

112. X. Hu, J. Sun, C. Qian, F. Liu, J. Yang, G.-h. Guo & Y. Gao. Low contact resistance in solid electrolyte-gated ZnO field-effect transistors with ferromagnetic contacts. Journal of Materials Chemistry C 4, 150-156 (2016).

113. H. Huang, Y. Huang, S. Wang, M. Zhu, H. Xie, L. Zhang, X. Zheng, Q. Xie, D. Niu & Y. Gao. Van Der Waals Heterostructures between Small Organic Molecules and Layered Substrates. Crystals 6, 113 (2016).

114. Y. Huang, J. Sun, J. Zhang, S. Wang, H. Huang, J. Zhang, D. Yan, Y. Gao & J. Yang. Controllable thin-film morphology and structure for 2, 7-dioctyl [1] benzothieno [3, 2-b][1] benzothiophene (C8BTBT) based organic field-effect transistors. Organic Electronics 36, 73-81 (2016).

115. L.-a. Kong, J. Sun, C. Qian, G. Gou, Y. He, J. Yang & Y. Gao. Ion-gel gated field-effect transistors with solution-processed oxide semiconductors for bioinspired artificial synapses. Organic Electronics 39, 64-70 (2016).

116. L. Li, X. Liu, L. Lyu, R. Wu, P. Liu, Y. Zhang, Y. Zhao, H. Wang, D. Niu, J. Yang & Y. Gao. Modification of Ultrathin NPB Interlayer on the Electronic Structures of the CH3NH3PbI3/NPB/MoO3 Interface. The Journal of Physical Chemistry C 120, 17863-17871 (2016).

117. S. Li, B. Yang, R. Wu, C. Zhang, C. Zhang, X.-F. Tang, G. Liu, P. Liu, C. Zhou & Y. Gao. High-quality CH 3 NH 3 PbI 3 thin film fabricated via intramolecular exchange for efficient planar heterojunction perovskite solar cells. Organic Electronics 39, 304-310 (2016).

118. X. Li, K. Hu, B. Lyu, J. Zhang, Y. Wang, P. Wang, S. Xiao, Y. Gao & J. He. Enhanced Nonlinear Optical Response of Rectangular MoS2 and MoS2/TiO2 in Dispersion and Film. (2016).

119. F. Liu, C. Qian, J. Sun, P. Liu, Y. Huang, Y. Gao & J. Yang. Solution-processed lithium-doped zinc oxide thin-film transistors at low temperatures between 100 and 300° C. Applied Physics A 122, 311 (2016).

120. L. Lyu, D. Niu, H. Xie, N. Cao, H. Zhang, Y. Zhang, P. Liu & Y. Gao. Orientation-dependent energy level alignment and film growth of 2, 7-diocty [1] benzothieno [3, 2-b] benzothiophene (C8-BTBT) on HOPG. The Journal of chemical physics 144, 034701 (2016).

121. J. Ouyang, M. Long, X. Zhang, D. Zhang, J. He & Y. Gao. Modulating the spin transport behaviors in ZBNCNRs by edge hydrogenation and position of BN chain. AIP Advances 6, 035116 (2016).

122. C. Qian, J. Sun, L.-a. Kong, G. Gou, J. Yang, J. He, Y. Gao & Q. Wan. Artificial Synapses Based on in-Plane Gate Organic Electrochemical Transistors. ACS applied materials & interfaces 8, 26169-26175 (2016).

123. C. Wang, Y. Li, X. Xu, C. Wang, F. Xie & Y. Gao. Degradation of co-evaporated perovskite thin film in air. Chemical Physics Letters 649, 151-155 (2016).

124. Y. Wang, S. Liu, J. Yuan, P. Wang, J. Chen, J. Li, S. Xiao, Q. Bao, Y. Gao & J. He. Ultra-broadband Nonlinear Saturable Absorption for Two-dimensional Bi2TexSe3− x Nanosheets. Scientific reports 6, 33070 (2016).

125. Y. Wang, H. Mu, X. Li, J. Yuan, J. Chen, S. Xiao, Q. Bao, Y. Gao & J. He. Observation of large nonlinear responses in a graphene-Bi2Te3 heterostructure at a telecommunication wavelength. Applied Physics Letters 108, 221901 (2016).

126. H. Wei, Y. Fang, P. Mulligan, W. Chuirazzi, H.-H. Fang, C. Wang, B. R. Ecker, Y. Gao, M. A. Loi & L. Cao. Sensitive X-ray detectors made of methylammonium lead tribromide perovskite single crystals. Nature Photonics 10, 333-339 (2016).

127. D. Wu, H. Huang, X. Zhu, Y. He, Q. Xie, X. Chen, X. Zheng, H. Duan & Y. Gao. E’’Raman Mode in Thermal Strain-Fractured CVD-MoS2. Crystals 6, 151 (2016).

128. R. Wu, B. Yang, C. Zhang, Y. Huang, Y. Cui, P. Liu, C. Zhou, Y. Hao, Y. Gao & J. Yang. Prominent efficiency enhancement in perovskite solar cells employing silica-coated gold nanorods. The Journal of Physical Chemistry C 120, 6996-7004 (2016).

129. H. Xie, D. Niu, L. Lyu, H. Zhang, Y. Zhang, P. Liu, P. Wang, D. Wu & Y. Gao. Evolution of the electronic structure of C60/La0. 67Sr0. 33MnO3 interface. Applied Physics Letters 108, 011603 (2016).

130. H. Xie, X. Liu, L. Lyu, D. Niu, Q. Wang, J. Huang, and Y. Gao, “Effects of precursor ratios and annealing on electronic structure and surface composition of CH3NH3PbI3 perovskite films,” J. Phys. Chem. C120 (1), 215 (2016).

131. J. Xiong, B. Yang, C. Cao, R. Wu, Y. Huang, J. Sun, J. Zhang, C. Liu, S. Tao & Y. Gao. Interface degradation of perovskite solar cells and its modification using an annealing-free TiO 2 NPs layer. Organic Electronics 30, 30-35 (2016).

132. D. Zhang, M. Long, F. Xie, J. Ouyang, H. Xu & Y. Gao. Hydrogenations and electric field induced magnetic behaviors in armchair silicene nanoribbons. Scientific reports 6 (2016).

133. J. Zhang, X. Yu, W. Han, B. Lv, X. Li, S. Xiao, Y. Gao & J. He. Broadband spatial self-phase modulation of black phosphorous. Optics letters 41, 1704-1707 (2016).

134. Z. Zheng, J. Jiang, J. Guo, J. Yang & Y. Gao. Bio-inspired coplanar-gate-coupled ITO-free oxide-based transistors employing natural nontoxic bio-polymer electrolyte. Organic Electronics 37, 474-478 (2016).

135. M. Zhu, L. Lyu, D. Niu, H. Zhang, S. Wang & Y. Gao. Effect of a MoO 3 buffer layer between C8-BTBT and Co (100) single-crystal film. RSC Advances 6, 112403-112408 (2016).

136. Chuan Qian, Jia Sun, Lei Zhang, Haipeng Xie, Han Huang, Junliang Yang, and Yongli Gao, "Air-stable and high-performance organic field-effect transistors based on ordered, large-domain phthalocyanine copper thin film," Synth. Met. 210, 336 (2015).

137. Peng Liu, Xiaoliang Liu, Lu Lyu,1 Haipeng Xie, Hong Zhang, Dongmei Niu, Han Huang, Cheng Bi, Zhengguo Xiao, Jinsong Huang, and Yongli Gao, “Interfacial electronic structure at the CH3NH3PbI3/MoOx interface,” Appl. Phys. Lett. 106, 193903 (2015).

138. Y.Z. Li, X.M. Xu, C.C. Wang, C.G. Wang, F.Y. Xie, and Y.L. Gao, “Degradation by Exposure of Co-Evaporated CH3NH3PbI3 Thin Films,” J. Phys. Chem. C 119, 23996 (2015).

139. L. Lyu, D.M. Niu, H.P. Xie, N.T. Cao, and Y.L. Gao, “Interface energy level alignment and thin film growth of C8-BTBT on MoS2,” Chinese J. Lumin. 36, 875 (2015).

140. L. Ciammaruchi, C. Wang, Y. Gao, and C.W. Tang, “Delineation of degradation patterns of C-60-based organic solar cells under different environments,” J. Appl. Phys. 117, 245504 (2015); doi: 10.1063/1.4923091

141. Y.Z. Li, X.M. Xu, C.C. Wang, C.G. Wang, F.Y. Xie, J.L. Yang, and Y.L. Gao, “Investigation on thermal evaporated CH3NH3PbI3 thin films,” AIP Adv. 5, 097111 (2015). doi:10.1063/1.4930545

142. R.S. Wu, J. Xiong, P. Liu, C. Zhou, H. Huang, Y.L. Gao, B.C. Yang, J.L. Yang, “Efficient Electron-Blocking Layer-Free Planar Heterojunction Perovskite Solar Cells with a High Open-Circuit Voltage,” Org. Elec. 26, 265 (2015).

143. C. Wang, X.L. Liu, C.C. Wang, J. Kauppi, and Y. Gao, “Electronic Structure Evolution in Doping of Fullerene (C60) by ultra-thin layer Molybdenum Trioxide,” J. Appl. Phys. 118, 085304 (2015).

144. H. Xie, H. Huang, N. Cao, C. Zhou, D.-M. Niu, and Yongli Gao, “Effects of annealing on structure and composition of LSMO thin films,” Phys. B447, 14 (2015).

145. Chuan Qian, Jia Sun, Lei Zhang, Han Huang, Junliang Yang, and Yongli Gao, “Crystal-Domain Orientation and Boundary of Organic Semiconductor Thin Film Investigated by in-situ Kelvin Probe Force Microscopy,” J. Phys. Chem. C119, 14965 (2015).

146. Lei Zhang, Yingguo Yang, Lu Lvyu, Hong Zhang, Ningtong Cao, Haipeng Xie, Xingyu Gao, Dongmei Niu, Han Huang, and Yongli Gao, “Thickness Dependent Air-Exposure Induced Phase Transition of CuPc Ultra-Thin Films to Well-Ordered One-Dimensional Nanocrystals on Layered Substrates,” J. Phys. Chem. C119, 4217 (2015).

147. Youzhen Li, Xuemei Xu, Chenggong Wang, Congong Wang, Fangyan Xie, Jinsong Huang, and Yongli Gao, “Surface Analytical Investigation on Organometal Triiodide Perovskit,” MRS Proceedings, in press.

148. Jian Xiong, Bingchu Yang, Runsheng Wu, Chenghao Cao, Yulan Huang, Chengbin Liu, Zhikun Hu, Han Huang, Yongli Gao, and Junliang Yang, “Efficient and Non-hysteresis CH3NH3PbI3/PCBM Planar Heterojunction Solar Cells,” Org. Elec. 24, 106 (2015).

149. Chenggong Wang, Xiaoliang Liu, and Yongli Gao, “Molecular Orientation of Copper Phthalocyanine (CuPc) Thin Films on Different Monolayers of Fullerene (C60) on SiO2/ Highly Oriented Pyrolytic Graphite (HOPG),” Appl. Phys. Lett. 106, 121603 (2015).

150. Jin Xiao, Mengqiu Long, Xiaojiao Zhang, Jun Ouyang, Hui Xu, and Yongli Gao, “Theoretical predictions on the electronic structure and charge carrier mobility in 2D Phosphorus sheets,” Science Rep. 5, 9961 (2015).

151. Fangmei Liu, Jia Sun, Si Xiao, Wenglong Huang, Shaohua Tao, Yi Zhang, Yongli Gao, and Junliang Yang, “Controllable Fabrication of Copper Phthalocyanine Nanostructure Crystals,” Nanotech. 26, 225601 (2015).

152. Chuan Qian, Jia Sun, Junliang Yang, and Yongli Gao, “Flexible organic field-effect transistors on biodegradable cellulose paper with efficient reusable ion gel dielectrics,” RSC Adv. 5, 14567 (2015).

153. I. Irfan and Y. Gao, “Improvement of Charge Transfer Between Electrode and Semiconductor by Thin Metal Oxide Insertion,” in Progress in High-Efficient Solution Process Organic Photovoltaic Devices, Ed. Y. Yang and G. Li, 67-99 (Springer-Verlag, Berlin, 2015).

154. Chenggong Wang, Xiaoliang Liu, Congcong Wang, Zhengguo Xiao, Cheng Bi, Yuchuan Shao, and Jinsong Huang, and Yongli Gao, “Surface Analytical Investigation on Organometal Triiodide Perovskite,” J. Vac. Sci. Tech. B33, 032401 (2015).

155. Chenggong Wang, Congcong Wang, Xiaoliang Liu, John Kauppi, Yuchuan Shao, Zhengguo Xiao, Cheng Bi, Jinsong Huang, and Yongli Gao, “Electronic Structure Evolution of Fullerene on CH3NH3PbI3,” Appl. Phys. Lett. 106, 111603 (2015).

156. C. Fu, K. Savino, A. Zeng, B. Guan, D. Olvera, C. Wang, B. Song, H. Awad, Y. Gao, and M. Z. Yates, “Large Stored Charge in Electrochemically Synthesized Hydroxyapatite,” Chem. Mater. 27, 1164 (2015).

157. X. Liu, C.G. Wang, C.C. Wang, I. Irfan, and Y. Gao, “Interfacial Electronic Structures of Buffer-modified C60/Pentacene-Based Charge Generation Layer,” Org. Elec. 17, 325 (2015).

158. Haichao Duan, Junliang Yang, Lin Fu, JianXiong, Bingchu Yang, Jun Ouyang, Conghua Zhou, Han Huang, and Yongli Gao, “Interface modification of organic photovoltaics by combining molybdenum oxide (MoOx) and molecular template layer,” Thin Solid Film 547, 146 (2015).

159. J. Xiong, B. Yang, J. Yuan, L. Fan, X. Hu, H. Xie, L. Lv, R. Cui, Y. Zou, C. Zhou, D.-M. Niu, Y. Gao, and J.L. Yang, “Efficient organic photovoltaics using solution-processed, annealing- free TiO2 nanocrystalline particles as an interface modification layer,” Org. Elec. 17, 253 (2015).

160. X. Liu, C.G. Wang, L. Lyu, C.C. Wang, Z.G. Xiao, C. Bi, J.S. Huang, and Y. Gao, “Electronic structures at the interface between Au and CH3NH3PbI3,” Phys. Chem. Chem. Phys. 17, 896 (2015).

161. C.G. Wang, I. Irfan, and Y. Gao, “Protection of MoO3 High Work Function by Organic Thin Film,” Appl. Phys. Lett. 105, 181602 (2014).

162. C.G. Wang, Irfan, and Y. Gao, “Manipulation of interface electronic structure by thin metal oxide films,” MRS Online Proceedings Library 1537, mrss13-1537-b03-06 (2014). (Invited paper)

163. C.G. Wang and Y. Gao, “Electronic Structure Evolution in Doping of Fullerene (C60) by Molybdenum Trioxide,” Appl. Phys. Lett. 105, 111601 (2014).

164. Qi Wang, Yuchuan Shao, Haipeng Xie, Lu Lyu, Xiaoliang Liu, Yongli Gao, and Jinsong Huang, “Qualifying composition dependent p and n self-doping in CH3NH3PbI3,” Appl. Phys. Lett. 105, 163508 (2014).

165. W. Xia, H. Lin, H.N. Wu, Irfan, C. Wang, Y. Gao, and C.W. Tang, “Te/Cu Bi-layer: A Low Resistence Contact Buffer for Thin Film CdS/CdTe Solar Cell,” Sol. En. Mater. Sol. Cell 128, 411 (2014).

166. N.T. Cao, L. Zhang, L. Lu, H.P. Xie, H. Huang, D.-M. Niu, and Y.L. Gao, “Van der Waals heterostructure of CuPc/MoS2(0001),” ACTA Phys. Sinica 63, 167903 (2014).

167. C. Bi, Y. Shao, Y. Yuan, Z. Xiao, C. Wang, Y. Gao, and J. Huang, “Understanding the formation and evolution of interdiffusion grown organolead halide perovskite thin films by thermal annealing,” J. Mater. Chem. A2, 18508 (2014).

168. S. Yan, M. Long, X. Zhang, J. He, H. Xu, and Y. Gao, “Spin-filtering, rectifying and negative differential resistance behavior in Co(dmit)2 molecular devices with monoatomic (C, Fe, Au) electrodes,” Spin 116, 1440016 (2014).

169. C. Wang, Irfan, X.L. Liu, and Y. Gao, “The Role of Molybdenum Oxide for Organic Electronics: Surface Analytical Studies,” J. Vac. Sci. Tech. 32, 040801 (2014). (Invited review)

170. Z. Xiao, C. Bi, Y. Shao, Q. Dong, Q. Wang, Y. Yuan, C.G. Wang, Y. Gao, and J.S. Huang, “Efficient, high yield perovskite photovoltaic devices grown by interdiffusion of solution-processed precursor stacking layers,” Ener. Envir. Sci. 7, 2619 (2014).

171. W. Huang, B. Yang, J. Sun, B. Liu, J. Yang, Y. Zou, J. Xiong, C. Zhou, and Y. Gao, “Organic field-effect transistor and its photoresponse using a benzo 1,2-b: 4,5-b ' difuran-based donor-acceptor conjugated polymer,” Org. Elec. 15, 1050 (2014).

172. Y. Zhou, T. Kurosawa, W. Ma, Y. Guo, L. Fang, K. Vandewal, Y. Diao, C.G. Wang, Q. Yan, J. Reinspach, J. Mei, A.L. Appleton, G.I. Koleilat, Y.L. Gao, S.A Salleo, H. Ade, Dahui Zhao, and Z. Bao, “High Performance All-Polymer Solar Cell via Polymer Side-Chain Engineering,” Adv. Mat. 26, 3767 (2014).

173. J. Xiong, B. Yang, C. Zhou, J. Yang, H. Duan, W. Huang, X. Zhang, X. Xia, L. Zhang, H. Huang, and Y. Gao, “Enhanced efficiency and stability of polymer solar cells with TiO2 nanoparticles buffer layer,” Org. Elec. 15, 835-843 (2014).

174. Jin Xiao, Meng-Qiu Long Xinmei Li, Hui Xu, Han Huang, and Yongli Gao, “Theoretical Prediction of Electronic Structure and Carrier Mobility in Single-walled MoS2 Nanotubes,” Scientific Reposts 4, 4327 (2014).

175. X. Liu, S.J. Yi, C.G. Wang, C.C. Wang, and Y. Gao, “Electronic Structure Evolution and Energy Level Alignment at C60/TAPC/MoOx/ITO Interfaces,” J. Appl. Phys. 115, 163708 (2014).

176. H. Wang, P. Wei, Y. Li, J. Han, H.R. Lee, B.D. Naab, N. Liu, C. Wang, E. Adijanto, B.C. K. Tee, S. Morishita, Q. Li, Y. Gao, Y. Cui, and Z. Bao, “Tuning the threshold voltage of carbon nanotube transistors by n-type molecular doping for robust and flexible complementary circuits,” PNAS 111, 4776 (2014).

177. X. Liu, C.G. Wang, Irfan, S.J. Yi, and Yongli Gao, “Effect of oxygen plasma treatment on air exposed MoOx thin film,” Org. Elec. 15, 977 (2014).

178. W. Wan, H. Li, H. Huang, S. L. Wong, L. Lv, Y. L. Gao, and A. T. S. Wee, “Incorporating Isolated Molybdenum (Mo) Atoms into Bilayer Epitaxial Graphene on 4H-SiC(0001),” ACS Nano 8, 970 (2014)

179. Jia Sun, Chuan Qian, Wenlong Huang, Junliang Yang, and Yongli Gao, “Ion-dependent gate dielectric characteristics of ion-conducting SiO2 solid-electrolytes in oxide field-effect transistors,” Phys. Chem. Chem. Phys. 16, 7455 (2014).

180. J. Sun, W.L. Huang, C. Qian, J.L. Yang, and Y.L. Gao, “Mobility enhancement of SnO2 nanowire transistors gated with nanogranular SiO2 solid electrolyte,” Phys. Chem. Chem. Phys. 16, 1084 (2014).

181. H. Ding and Yongli Gao, “Photoemission Studies of the Electronic Structure of Alkali Metal Doped Molecular Organic Semiconductors,” in Doping: Properties, Mechanisms and Applications, 107-220, Ed. L. Yu (Nova Science Publishers, New York, 2014).

182. C.G. Wang and Y. Gao, “Manipulation of interface electronic structure by thin metal oxide films,” MRS Proc. 1537, 306 (2013).

183. C.G. Wang, Irfan and Y. Gao, “Effect of air exposure of MoO3 film underneath thin CuPc layers,” MRS Proc. 1493, 287 (2013).

184. B.C. Yang, H.C. Duan, C.H. Zou, Y.L. Gao, and J.L. Yang, “Ordered Nanocolumn-Array Organic Semiconductor Thin Films with Controllable Molecular Orientation,” Appl. Surf. Sci. 286, 104-108 (2013).

185. Chenggong Wang, Irfan, Alexander Turinske, and Yongli Gao, “Orientation-dependent ionization potential of CuPc and energy level alignment at C60/CuPc interface,” Appl. Phys. B113, 361 (2013).

186. M. Vosgueritchian, M. Ramuz, P. Wei, C. Wang, Y. Gao, and Z. Bao, “Evaluation of Solution Processable Carbon Based Electrodes for all Carbon Solar Cells,” ACS Nano, 6, 10384 (2012).

187. C.G. Wang, Irfan, and Y. Gao, “Methods to Protect and Recover Work Function of Air Exposed Metal Oxide Films,” Proceedings of 2012 MRS Fall Meeting 1493 (2012) DOI: mrsf12-1493-h0809.

188. Chenggong Wang, Irfan, Alexander Turinske, and Yongli Gao, “Pinning of fullerene lowest unoccupied molecular orbital edge at the interface with standing up copper phthalocyanine,” Thin Solid Film 525, 64 (2012).

189. Irfan Irfan, Sachiko Graber, Franky So, and Yongli Gao，“Interplay of cleaning and de-doping in oxygen plasma treated high work function indium tin oxide (ITO),” Org. Elec. 13, 2028 (2012).

190. Irfan, A.J. Turinske, Zhenan Bao, and Yongli Gao, “Work function recovery of air exposed molybdenum oxide thin films,” Appl. Phys. Lett. 101, 093305 (2012).

191. Sondra L. Hellstrom, Michael Vosgueritchian, Randall M. Stoltenberg, Irfan Irfan, Mallory Hammock, Bril Wang, Chuangcheng Jia, Xuefeng Guo, Yongli Gao, Zhenan Bao, “Strong and stable doping of carbon nanotubes and graphene by MoOx for transparent electrodes,” Nano Lett. 12, 3574 (2012). DOI: 10.1021/nl301207e.

192. H. Lin, W. Xia, H.N. Wu, C.W. Tang, I. Irfan, Y. Gao, “MoOx as an Efficient and Stable Back Contact Buffer for Thin Film CdTe Solar Cells,” MRS Online Proc. 1447 DOI: http://dx.doi.org/10.1557/opl.2012.1164 (2012).

193. Irfan, H. Ding, Yongli Gao,W. Xia, H. Lin, and C. W. Tang, “Nitric-phosphoric acid etching effects on the surface chemical composition of CdTe thin film,” Thin Solid Films 520, 1988 (2012).

194. Irfan and Y. Gao, “Metal-Oxides Hole Injection/Extraction Layer in Organic Semiconductor Devices,” ECS Transactions 35(19), 11 (2012).

195. Irfan, Y. Gao, “Effects of exposure and air annealing on MoOx thin films,” J. Photonics for Energy 2, 021213-12 (2012).

196. Jegadesan Subbiah, Chad M. Amb, Irfan Irfan, Yongli Gao, John R. Reynolds, and Franky So, “High-Efficiency Inverted Polymer Solar Cells with Double Interlayer,” ACS Appl. Mater. Interf. 4, 866 (2012).

197. Irfan Irfan, H. Lin, W. Xia, H. S. Wu, C. W. Tang, and Y. Gao, “The effect of MoOx inter-layer on thin film CdTe/CdS solar cell”, Sol. Ener. Mater. Sol. Cells 105, 86 (2012).

198. Irfan, C.G. Wang, A.J. Turinske, and Y. Gao, “Methods to protect and recover work function of air exposed transition metal oxide thin films,” Proc. SPIE 8476, 847616 (2012).

199. Hao Lin, Irfan, Wei Xia, Hsiang N. Wu, Yongli Gao, Ching W. Tang, “MoOx back contact for CdS/CdTe thin film solar cells: Preparation, device characteristics, and stability,” Sol. En. Mat. Sol. Cells, 99, 349 (2012).

200. Irfan, H. Ding, and Y Gao, "Photoemission Spectroscopy Characterization of Attempts to Deposit MoO2 Thin Film," Int. J. Photoenergy, 2011, 314702, (2011). doi:10.1155/2011/314702

201. Irfan, M. Zhang, H. Ding, C. W. Tang and Y. Gao, "Strong interface p-doping and band bending in C60 on MoOx", J. Org. Elec. 12, 1588 (2011).

202. Irfan, H. Ding, F. So, and Y. Gao, “Oxide insertion layer in organic semiconductor devices,” J. Photo. Energy 1, 011105 (2011).

203. H. Ding and Yongli Gao, “Rubrene electronic structure, interface energy level alignment, and growth dynamics,” Proc. SPIE 7778, 77780J (2011).

204. H. Ding, Irfan, F. So, and Yongli Gao, “Interface study of insertion layers in organic semiconductor devices,” Proc. SPIE 7415, 74150J-74150J-14(2010).

205. Irfan, H. Ding, Yongli Gao, C. Small, D.Y. Kim, J. Subbiah, and F. So, “Energy level evolution of air and oxygen exposed molybdenum trioxide films,” Appl. Phys. Lett. 96, 243307 (2010).

206. M. Zhang, Irfan, H. Ding, Yongli Gao, and C. W. Tang, “Organic Schottky barrier solar cells based on MoOX/C60 junction,” Appl. Phys. Lett. 96, 183301 (2010).

207. H. Ding, C. Reese, A. J. Mäkinen, Z. Bao, and Y. Gao, “Angle-resolved photoemission study of rubrene single crystal,” Appl. Phys. Lett. 96, 222106 (2010).

208. Irfan, H. Ding, and Yongli Gao, D.-Y. Kim, J. Subbiah, G. Sarasqueta, and F. So, “Energy level evolution of molybdenum trioxide inter-layer between indium-tin-oxide (ITO) and organic semiconductor,” Appl. Phys. Lett., 96, 073304 (2010).

209. H. Ding and Y. Gao, “Evolution of the electronic structure of alkali-metal-doped copper-phthalocyanine (CuPc) on different metal substrates,” J. Org. Elec. 11, 1786 (2010).

210. C. C. Zhao, X. H. Chen, C. Gao, M. K. Ng, H. Ding, K. Park, and Y. Gao, “New organic semiconductors for thin-film transistors: Synthesis, characterization, and performance of 4H-indeno[1,2-b]thiophene derivatives,” Synthetic Metals, 159, 995, (2009).

211. Yasuhiro Shirai, Jason M. Guerrero, Takashi Sasaki, Tao He, Huanjun Ding, Guillaume Vives, Byung-Chan Yu, Long Cheng, Austen K. Flatt, Priscilla G. Taylor, Yongli Gao, and James M. Tour, “Fullerene/Thiol-Terminated Molecules,” J. Org. Chem. 74, 7885 (2009).

212. Y. Gao, “Surface Analytical Studies of Interfaces in Organic Semiconductor Devices,” Materials Sci. Engr. Rep. 68, 39 (2010).

213. Y. Gao, “Interface in Organic Semiconductor Devices: Dipole, Doping, Band Bending, and Growth,” in Organic Electronics :Materials, Processing, Devices, and Applications, Ed. F. So, 141 (Taylor & Francis CRC Press, New York, 2009).

214. D.Y. Kim, F. So, and Y. Gao, “Aluminum phthalocyanine chloride/C-60 organic photovoltaic cells with high open-circuit voltages,” Sol. E. Mat. Sol. Cells 93, 1688 (2009).

215. Do Young Kim, Jegadesan Subbiah, Galileo Sarasqueta, and Franky So, Huanjun Ding, Irfan and Yongli Gao, “The effect of molybdenum oxide interlayer on organic photovoltaic cells,” Appl. Phys. Lett. 95, 093304 (2009).

216. J. H. Wei, Y.L. Gao, and X.R.Wang, “Inverse Square-Root Field Dependence of Conductivity in Organic Field-Effect Transistors,” Appl. Phys. Lett. 94, 073301 (2009).

217. Huanjun Ding, Kiwan Park, Yongli Gao, Do Young Kim and Franky So, “Electronic structure and interactions of LiF doped tris (8-hydroxyquinoline) aluminum (Alq),” Chem. Phys. Lett. 473, 92 (2009).

218. H.J. Ding, Kiwan Park, and Y. Gao, “Evolution of the Unoccupied States in Alkali Metal-doped Organic Semiconductor,” J. Elec. Spec. Relat. Phen. 174, 45 (2009).

219. H. Ding and Y. Gao, “Electronic structure at rubrene metal interfaces,” Appl. Phys. A95, 89 (2009).

220. Y. Gao, “Organic/Metal Interface Properties,” in Introduction to Organic Optoelectronic Materials and Devices, Ed. S. Sun and L. Dalton, 637 (Taylor & Francis CRC Press, New York, 2008).

221. M. Cinchetti, K. Heimer, J.-P. Wüstenberg, O. Andreyev, M. Bauer, S. Lach, C. Ziegler, Y. Gao, and M. Aeschlimann, “Determination of spin injection and transport in a ferromagnet/organic semiconductor heterojunction by two-photon photoemission,” Nature Material, 8, 115 (2009).

222. H.J. Ding, Y. Gao, H. Wang, and D. Yan, “Band Bending and Debye Screening in F16CuPc/BP2T Ambipolar Organic Thin Film Transistor,” SPIE Proc. 7054, 70540C, (2008).

223. K. Park, H. Ding, F. So and Y. Gao, “Mechanism of LiF interlayer for electron injection,” SPIE Proc. 7051, 70511V (2008).

224. H. Ding, K.W. Park, and Y. Gao, “Electronic structure of doping in organic semiconductor,” SPIE Proc. 7051, 705111 (2008).

225. Z.L. Zhang, T. Asano, H. Uno, R. Tero, M. Suzui, S. Nakao, T. Kaito, K. Shibasaki, M. Tominaga, Y. Utsumi, Y.L. Gaof, T. Urisu, “Fabrication of Si-based planar type patch clamp biosensor using silicon on insulator substrate,” Thin Solid Films 516, 2813 (2008).

226. H. Ding, Y. Gao, M. Cinchetti, J.-P. Wustenberg, M. Sanchez-Albaneda, O. Andreyev, M. Bauer, and M. Aeschlimann, “Spin Injection and Spin Dynamics at the CuPc/GaAs Interface,” Phys. Rev. B78, 075311 (2008).

227. H. Ding, K.W. Park, and Y. Gao, “Unoccupied State Evolution in Cs-Doped Copper Phthalocyanine,” MRS Proc. 1029, F04-03 (2008).

228. H. Ding and Y. Gao, “Energy level alignment at the rubrene/metal interface,” MRS Proc., 1029, F04-03 (2008).

229. H. Ding and Y. Gao, “Modification on the Electronic Structure of Organic Semiconductors by Alkali Metal,” ECS Trans. 11, 1 (2008).

230. H. Ding, H. Wang, D. Yan, and Y. Gao, “Ambipolar Organic Thin Film Transistor and Electronic Structure of Interfaces,” ECS Trans. 11, 15 (2008).

231. H. Ding and Y. Gao, “The role of LiF for the electron injection in tris-(8-hydroxyquinoline) aluminum” , ECS Trans. 11, 25 (2008).

232. H. Ding, K. Green, and Y. Gao, “Electronic Structure Modification of Copper Phthalocyanine (CuPc) Induced by Intensive Na Doping,” Chem. Phys. Lett., 454, 229, (2008).

233. T. He, H. Ding, N. Peor, M. Lu, D.A. Corley, B. Chen, Y. Ofir, Y. Gao, S. Yitzchaik, and J. Tour, “Silicon/Molecule Interfacial Electronic Modifications,” J. Am. Chem. Soc. 130, 1699 (2008).

234. H. Ding and Y. Gao, “Evolution of the Unoccupied State in Cs-Doped Copper Phthalocyanine,” Appl. Phys. Lett. 92, 053309 (2008).

235. H. Ding, Y. Gao, M. Sanchez-Albaneda, J.-P. Wustenberg, M. Cinchetti, O. Andreyev, M. Bauer, and M. Aeschlimann, “Spin Injection and Spin Dynamics at CuPc/GaAs(100) Interface,” MRS Proc. 965, S09-49 (2007).

236. H. Ding and Y. Gao, “Photoemission Study of Oxygen and Au Modification of Doped Copper Phthalocyanine,” J. Appl. Phys. 102, 043703 (2007).

237. H. Ding and Y. Gao, “Au/LiF/tris-(8-hydroxyquinoline) aluminum interfaces,” Appl. Phys. Lett. 91, 172107 (2007).

238. Y. Gao, H. Ding, H. Wang, and D. Yan, “Electronic structure of interfaces between hexadecafluoro-phthalocyanine and 2,5-bis(4-biphenylyl) bithiophene,” Appl. Phys. Lett. 91, 142112 (2007).

239. H. Ding and Y. Gao, “Reversal of Doping Induced Energy Level Shift in Organic Semiconductors,” Internat. J. Nanosci. 6, 125 (2007).

240. H. Ding, S. Zorba, Y. Gao, L.P. Ma, and Y. Yang, “Photoemission study of tris(8-hydroxyquinoline) aluminum/aluminum oxide/tris(8-hydroxyquinoline) aluminum interface,” J. Appl. Phys. 100, 113706 (2006).

241. N. J. Watkins, A. J. Mäkinen, Y. Gao, M. Uchida, and Z. H. Kafafi, “Direct observation of the evolution of occupied and unoccupied energy levels of two silole derivatives at their interfaces with magnesium,” J. Appl. Phys. 100, 103706 (2006).

242. S. Zorba, Y. Shapir, and Y. Gao, "Fractal-mound growth of pentacene thin films," Phys. Rev. B74, 245410 (2006).

243. H. Ding and Y. Gao, “Alkali Metal Doping and Energy Level Shift in Organic Semiconductor Surfaces,” Appl. Surf. Sci. 252, 3943 (2006).

244. B.H. Hamadani, H. Ding, Y. Gao, and D. Natelson, “Doping dependent chargeinjection in organic field-effect transistors,” Phys. Rev. B72, 235302 (2005).

245. S. Pyo, L.P. Ma, J. He, Q.F. Xu, Y. Yang, and Y. Gao, “Experimental study on thickness-related electrical characteristics in organic/metal-nanocluster/organic systems,” J. Appl. Phys. 98, 54303 (2005).

246. A. Tanaka, L. Yan, N.J. Watkins, Y. Gao, “Femtosecond Time-resolved Two-photon Photoemission Study of Organic Semiconductor Copper Phthalocyanine Film,” J. Elec. Spec. Relat. Phen. 144, 327 (2005).

247. H. Ding and Y. Gao, “Reversal of Doping Induced Energy Level Shift: Au on Cs-doped Alq,” Appl. Phys. Lett. 87, 851918 (2005).

248. H. Ding and Y. Gao, “Electronic Structure of Cs Doping in Alq,” Appl. Phys. Lett. 86, 213508 (2005).

249. S. Zorba and Y. Gao, “Feasibility of Static Induction Transistor with Organic Semiconductors,” Appl. Phys. Lett. 86, 193508 (2005).

250. R. Krishnan, Q. Xie, J. Kulik, X.D. Wang, S. Lu, M. Molinari, Y. Gao, T.D. Krauss, P.M. Fauchet, “Effect of Oxidation on Charge Localization and Transport in a Single Layer of Silicon Nanocrystals,” J. Appl. Phys. 96, 654 (2004).

251. S. Zorba and Y. Gao, “Growth Kinetics of Ordered Pentacene Thin Films,” in Proc. Int. Conf. Synth. Metals 2004, (University of Wollongong, 2004).

252. N.J. Watkins and Y. Gao, “Energy Level Alignment of Pentacene and Dielectric Materials,” in Proc. Int. Conf. Synth. Metals 2004, (University of Wollongong, 2004).

253. L. Yan, N.J. Watkins, S. Zorba, and Y. Gao, “Metal-Organic Interface Dipole and Thermodynamic Equilibrium,” in Proc. Int. Conf. Synth. Metals 2004, (University of Wollongong, 2004).

254. Y. Gao and L. Yan, “Energy Level Shift in CuPc,” in Proc. Int. Conf. Synth. Metals 2004, (University of Wollongong, 2004).

255. Y. Gao, “Interface Electronic Structure and Organic Photovoltaic Devices,” in Organic Photovoltaics, Ed. S. Sun and N. Sariciftci, 421 (Taylor and Francis, New York, 2004).

256. N.J. Watkins, S. Zorba, and Y. Gao, “Interface Formation of Pentacene with Al2O3,” J. Appl. Phys. 96, 425 (2004).

257. Serkan Zorba and Yongli Gao, “Organic Nanofilm Growth,” in Encyclopedia of Nanoscience and Nanotechnology, Ed. H.S. Nalwa, Vol 8, 271 (2004).

258. N.J. Watkins and Y. Gao, “Interface Formation and Energy Level Alignment of Pentacene on SiO2,” J. Appl. Phys. 94, 5782 (2003).

259. Y. Gao and Li Yan, “Cs Doping and Energy Level Shift in CuPc,” Chem. Phys. Lett. 380, 451 (2003).

260. N.J. Watkins and Y. Gao, “Vacuum level alignment of pentacene on LiF/Au,” J. Appl. Phys. 94, 1289 (2003).

261. A. Tanaka, N.J. Watkins, and Yongli Gao, “Hot-Electron Relaxation in the Layered Semiconductor 2H-MoS2 Studied by Time-Resolved Two-Photon Photoemission Spectroscopy,” Phys. Rev. B67, 113315 (2003).

262. Xiaowei Teng, Donald Black, Neil J. Watkins, Yongli Gao, and Hong Yang, “Platinum-Maghemite Core-Shell Nanoparticles Using a Sequential Synthesis,” Nano Let. 3, 261 (2003).

263. Serkan Zorba, Li Yan, Neil J. Watkins, and Yongli Gao, “Kinetic Roughening Study of Perylene on Glass and Au Substrates,” MRS Proc., in press.

264. Li Yan, N.J. Watkins, C. W. Tang, and Yongli Gao, “Fermi Level Pinning in Cs Doped CuPc,” Synth. Met. 137, 1037 (2003).

265. N. J. Watkins, Li Yan, S. Zorba, and Yongli Gao, “Photoemission spectroscopy study of the interface formation in organic thin film transistors,” SPIE Proc. 4800, 192 (2003).

266. Serkan Zorba, Li Yan, Neil J. Watkins, and Yongli Gao, “Growth Front Kinetics of Perylene on Glass and Au Substrates,” SPIE Proc. 4801, 136 (2003).

267. N. J. Watkins, Li Yan, S. Zorba, Yongli Gao, and C. W. Tang, “Evidence of Electron and Hole Transfer in Metal/CuPc Interfaces,” SPIE Proc. 4800, 248 (2002).

268. Akinori Tanaka, Tazumi Nagasawa, Yuitsu Takeda, Neil J. Watkins and Yongli Gao, “Time-Resolved Two-Photon Photoemission Study of Dodecanethiolate-Passivated Ag Nanoparticles,” J. Phys. Soc. Japan 71, 3098 (2002).

269. Serkan Zorba, Li Yan, Neil J. Watkins, and Yongli Gao, “Kinetic Roughening Study of Perylene on Glass and Au Substrates,” Appl. Phys. Lett. 81, 5195 (2002).

270. N.J. Watkins, S. Zorba, L. Yan, and Y. Gao, “A Photoemission Spectroscopic Study of the Interface Formation in Organic Thin Film Transistors,” MRS Proc. 708, BB2.3 (2002).

271. Li Yan, N. J. Watkins, S. Zorba, Yongli Gao, and C. W. Tang, "Thermodynamic Equilibrium and Metal-Organic Interface Dipole," Appl. Phys. Lett. 81, 2752 (2002).

272. N. J. Watkins, Li Yan, and Yongli Gao, "Symmetry of Interfaces between Pentacene and Metals," Appl. Phys. Lett. 80, 4384 (2002).

273. L. Yan and Y. Gao, "Interfaces in Organic Light-Emitting Diodes," Thin Solid Films 417, 101 (2002).

274. Serkan Zorba, Quoc Toan Le, Neil J. Watkins, Li Yan, and Yongli Gao, "Morphology and Current-Voltage Measurement Studies of Pentacene by Atomic Force Microscopy," J. Nanosci. Nanotech. 1, 317 (2001).

275. N. J. Watkins, Quoc Toan Le, S. Zorba, Li Yan, Yongli Gao, S. F. Nelson, C. S. Kuo, and T. N. Jackson, "Photoemission Characterization of Interfaces between Au and Pentacene," SPIE Proc. 4466, 1 (2001).

276. Li Yan, N. J. Watkins, S, Zorba, Yongli Gao, and C. W. Tang, "Direct Observation of Fermi Level Pinning in Cs Doped CuPc Film," Appl. Phys. Lett. 79, 4148 (2001).

277. Y. Nonogaki, Y. Gao, H. Mekaru, T. Miyamae, and T. Urisu, “STM observation of surface nanostructures on Si(111) formed after synchrotron radiation stimulated cleaning,”　Transactions MRS Japan, 26, 751 (2001).

278. Y. Nonogaki, Y. Gao, H. Mekaru, and T. Urisu, "Nanostructure Formation on Si(111) Surface Assisted by Synchrotron Radiation Illumination -Characterization by Scanning Tunneling Microscopy," J. Elec. Spec. Relat. Phen. 119, 241 (2001).

279. Serkan Zorba, Q. Toan Le, Neil J. Watkins, Li Yan, and Yongli Gao, "Current-Voltage Measurements as a Function of Applied Tip Force on Pentacene by Conducting Probe Microscopy," MRS Proc. 660, JJ10.3 (2001).

280. N.J. Watkins ,Quoc Toan Le, S. Zorba, Li Yan, and Yongli Gao, "Interface Formation in Pentacene Based Thin Film Transistors: an Electronic and Morphological Study," MRS Proc. 660, JJ7.3 (2001).

281. Li Yan, Yongli Gao, M. G. Mason, and C.W. Tang, "Energy Level Alignment at Metal/Alq3 Interfaces Investigated by Photoemission Methods," MRS Proc. 660, JJ8.36 (2001).

282. A.J. Mäkinen, S. Schoemann, Yongli Gao, M.G. Mason, A.A. Muenter, and A.R. Melnyk, "Femtosecond Photoemission Study of Relaxation and Interface Charge Transfer Dynamics in Organic Photoreceptors," in Conjugated Polymer and Molecular Interfaces: Science and Technology for Photonic and Optoelectronic Applications, Ed. W.R. Salaneck, K. Seki, A. Kahn, and J. J. Pireaux (Marcel Dekker, New York, 2001).

283. L. Yan, M.G. Mason, C.W. Tang, and Yongli Gao, "Energy Level Alignment in Metal/Organic Interfaces: Ca/Alq3 and Al/Alq3," SPIE Proc. 4105, 84 (2001).

284. Li Yan, Yongli Gao, M.G. Mason, and C.W. Tang, "Photoemission Study of Energy Alignment at the Metal/Alq3 Interfaces," Appl. Surf. Sci. 175-176, 412 (2001).

285. M.G. Mason, C.W. Tang, L,-S. Hung, P. Raychaudhuri, J. Madathil, D.J. Giesen, L. Yan, Q.T. Le, Y. Gao, S.-T. Lee, L.S. Liao, L.F. Cheng, W.R. Salaneck, D.A. dos Santos, and J.L. Brédas, "The Interaction of Tris-(8-hydroxyquinoline) aluminum with Reactive Metals and the Role of LiF," J. of Appl. Phys. 89, 2756 (2001).

286. E.W. Forsythe and Y. Gao, “Interfaces in Organic Light Emitting Devices”, Book Chapter Review for “Handbook of Surfaces and Interfaces of Materials”, Ed. H.S. Nalwa, 286 (Academic Press, New York, 2001).

287. A.J. Mäkinen, S. Schoemann, Yongli Gao, M.G. Mason, A.A. Muenter, and A.R. Melnyk, "Femtosecond Photoemission Study of Excited State Dynamics in Organic Photoreceptors," SPIE Proc. 3940, 65, (2001).

288. V.K. Gupta, M.W. Koch, N.J. Watkins, Y. Gao, G.W. Wicks, "Molecular Beam Epitaxial Growth of BGaAs Ternary Compounds," J. Elec. Mat. 29, 1387 (2000).

289. F. Nuesch, E.W. Forsythe, Q.T. Le, Y. Gao, and L.J. Rothberg, “Importance of Indium Tin Oxide Surface Acido Basicity for Charge Injection into Organic Materials Based Light Emitting Diodes”, J. Appl. Phys., 87, 7973, (2000).

290. N. Koch, R. Pairleitner, Q.T. Le, E.W. Forsythe, Y. Gao, and G. Leising, “Photoemission Spectroscopic Investigation on the Interface Formation of a Ladder-Type Poly(para-phenylene) with Aluminum”, Appl. Phys. Lett. 76, 3738, (2000).

291. Y. Gao, H. Mekaru, T. Miyamae, and T. Urisu, "Scanning Tunneling Microscopy Study of Si(111) Surface Morphology after Removal of SiO2 by Synchrotron Radiation Illumination," Appl. Phys. Lett. 76, 1392 (2000).

292. Q.T. Le, E.W. Forsythe, F. Nuesch, L. Rothberg, Li Yan, and Yongli Gao, "Interface Formation between NPB and Processed Indium-Tin-Oxide," Thin Solid Films, 363, 42 (2000).

293. Q.T. Le, F. Nuesch, L.J. Rothberg, E.W. Forsythe, and Y. Gao, "Characterization of Treated Indium Tin Oxide Surface and Interface Formation with Phenyl Diamine,” SPIE Proc. 3797, 301 (2000).

294. A.J. Makinen, S. Schoemann, Y. Gao, M.G. Mason, A.A. Muenter, D.A. Mantell, A.R. Melnyk, and R.L. Headrick, "Femtosecond Excited State Dynamics in Organic Molecular Films," in Photoinduced Charge Transfer, Ed. L. Rothberg (World Scietific, New York, 2000).

295. E.W. Forsythe, M. Abkowitz, C.W. Tang, and Yongli Gao, "Growth Modes and Hole Injection Characteristics of Organic Films on Induim Tin Oxide," in Photoinduced Charge Transfer, Ed. L. Rothberg (World Scietific, New York, 2000).

296. Y. Gao, T. Miyamae, H. Mekaru, and T. Urisu, "Scanning Tunneling Microscopy Study of Surface Morphology of Si(111) after Synchrotron Radiation Stimulated Desorption of SiO2," J. of Vac. Sci. Tech., A18, 1153 (2000).

297. E.W. Forsythe, M.A. Abkowitz, and Yongli Gao, “The Influence of Copper Phthalocynanine on the Charge Injection and Growth Modes for Organic Light Emitting Diodes,” J. of Vac. Sci. Tech., A18, 1869 (2000).

298. E.W. Forsythe, M. Abkowitz, and Yongli Gao, “Tuning the Carrier Emission and Growth Modes,” J. of Phys. Chem. B104, 3948 (2000).

299. Quoc Toan Le, Li Yan, Yongli Gao, M. G. Mason, D. J. Giesen, and C. W. Tang, "Photoemission Study of Al/tris-(8-hydroxyquinoline) Aluminum and Al/LiF/tris-(8-hydroxyquinoline) Aluminum Interfaces," J. Appl. Phys. 87, 375 (2000).

300. A.J. Makinen, A.R. Melnyk, S. Schoemann, R.L. Headrick, and Yongli Gao, "Effect of Crystalline Domain Size on the Photophysical Properties of Thin Organic Molecular Films," Phys. Rev. B60, 14683 (1999).

301. A.J. Makinen, S. Xu, Z. Zhang, S.J. Diol, Yongli Gao, M.G. Mason, A.A. Muenter, D.A. Mantell, and A.R. Melnyk, "The Effect of Disorder on Excited State Dynamics in Organic Molecular Films," Appl. Phys. Lett. 74, 1296 (1999).

302. E.W. Forsythe, V.-E. Choong, C.W. Tang, and Yongli Gao, "Interface Analysis of Naphthyl-Substituted Benzidine Derivative and Tris-8-(hydroxyquinoline) Aluminum Using Ultra-Violet and X-Ray Photoemission Spectroscopy,” J. Vac. Sci. Tech. A17, 3429 (1999).

303. A.J. Makinen, S. Xu, Z. Zhang, S.J. Diol, Y. Gao, M.G. Mason, A.A. Muenter, D.A. Mantell, and A.R. Melnyk, "Morphology and Excited State Dynamics in Thin Organic Molecular Films Probed by Femtosecond Time-Resolved Photoemission Spectroscopy," J. Vac. Sci. Tech. A17, 2329 (1999).

304. E.W. Forsythe, Yongli Gao, L.G. Provost, and G.S. Tompa, “Photoemission Spectroscopy Analysis of ZnO:Ga Films for Display Applications,” J. Vac. Sci Tech. A17, 1761 (1999).

305. Quoc Toan Le, F. M. Avendano, E. W. Forsythe, Li Yan, C. W. Tang, and Yongli Gao, "X-Ray Photoelectron Spectroscopy and Atomic Force Microscopy Investigation of Stability Mechanism of Tris-(8-hydroxyquinoline) Aluminum Based Light-Emitting Diodes," J. Vac. Sci. Tech. A17, 2314 (1999).

306. F. Nuesch, L. J. Rothberg, E. W. Forsythe, Quoc Toan Le, and Yongli Gao, "A Photoelectron Spectroscopy Study on the Indium Tin Oxide Treatment by Acids and Bases," Appl. Phys. Lett. 74, 880 (1999).

307. E.W. Forsythe, D.C. Morton, T.Q. Le, C.W. Tang, and Yongli Gao, "Energy Level Alignment and Trap States in Doped Tris-8-(hydroxyquinoline) Using Thermally Stimulated Luminescence," SPIE Proc. 3623, 13 (1999).

308. Quoc Toan Le, M. G. Mason, Li Yan, V.-E. Choong, E. W. Forsythe, C. W. Tang, and Yongli Gao, "Interface Formation between Al and Ca with Tis-(8-hydroxyquinoline) Aluminum," SPIE Proc. 3623, 64 (1999).

309. Quoc Toan Le, F. Nuesch, L. J. Rothberg, E. W. Forsythe, and Yongli Gao, "Photoemission Study of Phenyl-Diamine Treated Indium Tin Oxide Interface," Appl. Phys. Lett. 75, 1357 (1999).

310. N.J. Watkins, G.W. Wicks, and Yongli Gao, "Oxidation study of GaN using x-ray photoemission spectroscopy," Appl. Phys. Lett. 75, 2602 (1999).

311. F.M. Avendano, E.W. Forsythe, Yongli Gao, and C.W. Tang “The Growth Modes of NPB on Indium Tin Oxide,” Synth. Met. 102, 910 (1999).

312. Quoc Toan Le, V.-E. Choong, M.G. Mason, C.W. Tang, and Yongli Gao, “Photoemission Study of Interfaces in Organic Light-Emitting Diodes,” Synth. Met. 102, 1014 (1999).

313. S. Xu, S.J. Diol, A. Makinen, L. Rothberg, Yongli Gao, M.G. Mason, A.A. Muenter, D.A. Mantell, and R.J.D. Miller, “Super-Radiant Decay in Two-Dimensional Layered Semiconductors,” Ultrafast Phenomena XI, 292 (Springer-Verlag, Berlin, 1999).

314. E.W. Forsythe, D.C. Morton, T.Q. Le, C.W. Tang, and Yongli Gao, “Trap States in Doped tris-8-(hydroxyquinoline) Using Thermally Stimulated Luminescence,” SPIE Proc. 3473, 23 (1999).

315. Y. Gao, “Surface Analytical Studies of Interface Formation in Organic Light Emitting Devices,” Acc. Chem. Res. 32, 247 (1999).

316. J. Cao, H.E. Elsayed-Ali, R.J.D. Miller, D.A. Mantell, and Y. Gao, “Femtosecond Photoemission Study of Ultrafast Electron Dynamics in Single Crystal Au(111) Films,” Phys. Rev. B58, 10948 (1998).

317. C. Hochfilzer, G. Leising, Y. Gao, E. Forsythe, and C. W. Tang, "Emission Process in Bi-Layer Organic Light Emitting Devices," Appl. Phys. Lett., 73, 2254 (1998).

318. E.W. Forsythe, D.C. Morton, C.W. Tang, and Yongli Gao, “Trap States of tris-8-(hydroxyquinoline) Aluminum and Naphthyl-Substituted Benzidine Derivative Using Thermally Stimulated Luminescence,” Appl. Phys. Lett. 73, 1457 (1998).

319. Ioannidis, E.W. Forsythe, Yongli Gao, M.W. Wu, and E.M. Conwell, “Current-Voltage Characteristics of Organic Light Emitting Diodes,” Appl. Phys. Lett . 72, 3038 (1998).

320. V.-E. Choong, M.G. Mason, C.W. Tang and Y. Gao, "Investigation of the Interface Formation Between Calcium and Tris-(8-hydroxy quinoline) aluminum," Appl. Phys. Lett. 72, 2689 (1998).

321. V.-E. Choong, Y. Park, and Y. Gao, M.G. Mason, and C.W. Tang, "Photoluminesence Quenching of Alq3 by Metal Deposition: A Surface Analytical Investigation," J. Vac. Sci. Technol. A16, 1838 (1998).

322. C. Hochfilzer, T. Jost, A. Niko, W. Graupner, G. Leising, C. W. Tang, E. Forsythe, Y. Gao, "Internal Field Distribution in Organic Light Emitting Devices With Double Layer Structure," Materials Research Society Symposium Proceedings 488, 121 (1998).

323. E.W. Forsythe, D.C. Morton, C.W. Tang, and Y. Gao, "Trap States of Tris-8-(hydroxyquinoline) Aluminum and Naphthyl-Substituted Benzidine Derivative Using Thermally Stimulated Luminescence," Proceeding of Materials Research Society Symposium, Boston, in press.

324. V.-E. Choong, Y. Park, Y. Gao, B.R. Hsieh, and C. W. Tang, "Luminescence of Organic Materials: Metal Induced Quenching and Its Revival," Proceeding of The Society for Imaging Science and Technology 50th Annual Conference, in press.

325. Y. Gao, "Interface Formation in Polymeric Light Emitting Diodes: a Review of Modeling and Surface Analytical Measurements," in Polymer-Solid Interfaces: from Model to Real Systems, J.J. Pireaux, J. Delhalle, and P. Rudolf, Eds., 365 (PUN, Namur, Belgium, 1998).

326. Y. Park, V. Choong, Y. Gao, B.R. Hsieh, C.W. Tang, "Interface Formation of PPV Oligomer with Ca: a Model System for Metal/Polymer Interface," in Polymer-Solid Interfaces: from Model to Real Systems, J.J. Pireaux, J. Delhalle, and P. Rudolf, Eds., 147 (PUN, Namur, Belgium, 1998).

327. V. Choong, Y. Park, B.R. Hsieh, and Y. Gao, "Interface Formation in Organic Semiconductor Devices," in Electrical and Optical polymer Systems: Fundamentals, Methods, and Applications, edited by D. L. Wise, G. Wnek, D. J. Trantolo, and T. M. Cooper, (Marcel Dekker, New York, in press).

328. W.C. Wan, Y. Gao, T.E. Goodwin, S.A. Gonzalez, W.A. Feld, and B.R. Hsieh, "Phenylated Poly(p-phenylene vinylenes) Prepared via the Chlorine Precursor Route (CPR)," Macromolecular Symposia, 125, 205 (1998).

329. B.R. Hsieh, W.C. Wan, Y. Yu, Y. Gao, T.E. Goodwin, S.A. Gonzalez, and W.A. Feld, "Synthesis of Highly Phenylated Poly(p-phenylenevinylenes) via a Chlorine Precursor Route," Macromol. 31, 631 (1998).

330. V.-E. Choong, Y. Park, Y. Gao, B.R. Hsieh, and C.W. Tang, "Metal Induced Photoluminescence Quenching of a Phenylene Vinylene Oligomer and Its Recovery," Macromolecular Symposia, 125, 83 (1998).

331. H.G. Lee, S. Kim, C. Hwang, V. Choong, Y. Park, Y. Gao, and B.R. Hsieh, "A Study of Poly(p-phenylenevinylene) and its Derivatives Using X-ray Photoelectron Spectroscopy," J. Appl. Phys. 82, 4962 (1997).

332. V.-E. Choong, Y. Park, B.R. Hsieh, C.W. Tang, and Y. Gao, "Effects of Metals on Luminescence of Organic Light Emitting Materials," Polymer Preprints 38, 392 (1997).

333. V.-E. Choong, Y. Park, B.R. Hsieh, C.W. Tang, and Y. Gao, "Interfaces in Organic Light Emitting Devices: Quenching of luminescence," in Organic Light-Emitting Materials and Devices, Z.H. Kafafi, Ed., Procedings of SPIE Vol. 3148, 274 (1997).

334. T.P. Nguyen, S. Lefrant, S. deVos, and Y. Gao, "Interfacial Reactions in Poly (phenylene vinylene)-Metal," Synth. Met. 84, 659 (1997).

335. S. Xu, C.C. Miller, Y. Gao, D.A. Mantell, M.G. Mason, A.A. Muenter, B.A. Parkinson, and R.J.D. Miller, "Ultrafast Electron Dynamics in Two Dimensional Layered Systems: Two-Photon Photoemission Studies of SnS2," Chem. Phys. Lett. 272, 209 (1997).

336. W.C. Wan, H. Antoniadis, V.-E. Choong, H. Razafitrimo, Y. Gao, W.A. Feld, and B.R. Hsieh, "Halogen Precursor Route to Poly(2,3-diphenyl-p-phenylene vinylene) (DP-PPV): Synthesis, Photoluminescence, Electroluminescence and Photoconductivity," Macromolecules 30, 6567 (1997).

337. V. Choong, Y. Park, N, Shivaparan, C.W. Tang, and Y. Gao, "Deposition Induced Photoluminescence Quenching of Tris-(8-Hydroxyquinoline) Aluminum," Appl. Phys. Lett. 71, 1005 (1997).

338. J. Cao, Y. Gao, R.J.D. Miller, H. Elsayed-Ali, and D.A. Mantell, "Femtosecond Photoemission Study of Ultrafast Electron Dynamics on Cu(100)," Phys. Rev. B56, 1099 (1997).

339. Y. Park, V. Choong, B.R. Hsieh, C.W. Tang, and Y. Gao, "Gap-State Induced Photoluminescence Quenching of Phenylene Vinylene Oligomer and its Recovery by Oxidation," Phys. Rev. Lett. 78, 3955 (1997).

340. V. Choong, Y. Park, B.R. Hsieh, and Y. Gao, "Radiation Induced Photoluminescence Quenching of Phenylene Vinylene Oligomer Thin Films," Phys. Rev. B55, 15460 (1997).

341. S.A. Jenekhe, X. Zhang, X.L. Chen, V. Choong, J. Vitale, Y. Gao, and B.R. Hsieh, "Finite Size Effects on Electroluminescence of Nanoscale Semiconducting Polymer Heterojunctions," Chem. Mat. 9, 409 (1997).

342. Y. Park, V. Choong, B.R. Hsieh, C.W. Tang, T. Wehrmeister, K. Mullen, and Y. Gao, "Electron Spectroscopy Studies of Interface Formation Between Metal Electrodes and Luminescent Organic Materials," J. Vac. Sci. Technol. A15, 2574 (1997).

343. V. Choong, Y. Park, B.R. Hsieh, C.W. Tang, T. Wehrmeister, K. Mullen, and Y. Gao, "Effects of Metals on Luminescence of Organic Materials," J. Vac. Sci. Technol. A15, 1745 (1997).

344. S. Xu, C.C. Miller, D.A. Mantell, R.J.D. Miller, and Y. Gao, "Time-Resolved Photoemission Spectroscopy Studies of Layered Compounds," J. Vac. Sci. Technol. A15, 1510 (1997).

345. S. Diol, C.C. Miller, C.A. Schmuttenmaer, J. Cao, Y. Gao, D.A. Mantell, and R.J.D. Miller, "Photogenerated Hot Electron Dynamics at GaAs(100) Surfaces," J. Phys. D30, 1427 (1997).

346. V. Choong, Y. Park, Y. Gao, and B.R. Hsieh, "Quantum Molecular Quantum Mechanical Calculations of the Interface Formation between Al, Ca and Mg with Poly(Phenylene Vinylene) (PPV) Oligomers," J. Phys. D30, 1421 (1997).

347. C.C. Miller, S. Diol, C.A. Schmuttenmaer, J. Cao, D.A. Mantell, R.J.D. Miller, and Y. Gao, "Reverse surface photovoltaic effects in GaAs surface quantum wells," J. Phys. D30, 1416 (1997).

348. E. Ettedgui, B.R. Hsieh, and Y. Gao, "Interface Formation of Metals and Poly(p-Phenylene Vinylene): Surface Species and Band Bending," Polym. Adv. Technol. 8, 408 (1997).

349. E. Ettedgui, H. Razafitrimo, B.R. Hsieh, W.A. Feld, M.W. Ruckman, and Y. Gao, "Near Edge X-ray Absorption Fine Structure Study of Poly(2,3-diphenylphenylene vinylene) Following the Deposition of Metal," in Photonics and Optoeletronics Polymers, edited by S.A. Jenekhe and K.J. Wynne, 408 (Am. Chem. Soc., Washington, DC. 1997).

350. L.H. Guo, G.L. McLendon, H. Razafitrimo, and Y. Gao, "Photo-active and Electro-active Protein Films Prepared by Reconstitution with Metalloporphyrins Self-assembled on Gold," J. Mater. Chem. 6, 369-374 (1996).

351. H. Razafitrimo, B.R. Hsieh, and Y. Gao, "Imaging Surfaces of Thin Conjugated Polymer Films by Scanning Tunneling Microscope," Proceedings of Third Workshop on Industrial Applications of Scanned Probe Microscopy, Gaithersburg (1996).

352. B.R. Hsieh, V. Choong, H. Razafitrimo, Y. Gao, H. Antoniadis, D. Roitman, and W.A. Feld, "Light Emitting Diodes Based on Poly(p-phenylene vinylene)," Proceeding of The Society for Imaging Science and Technology 49th Annual Conference, 401 (1996).

353. V. Choong, Y. Park, B.R. Hsieh, C.W. Tang, T. Wehrmeister, K. Mullen, and Y. Gao, "Severe Photoluminescence Quenching of 1,4-bis[4-(3,5-di-tert-butylstyry)styryl]benzene upon Deposition of Submonolayer Ca," Polym. Preprints 37(2), 583 (1996).

354. H. Razafitrimo, B.R. Hsieh, T. Wehrmeister, K. Mullen, and Y. Gao, "Comparative Topographic Study of Differently Prepared Conjugated Polymer and Oligomer Films Using Scanning Tunneling Microscope," Polym. Preprints, 37(2), 581 (1996).

355. B.R. Hsieh, V. Choong, H. Razafitrimo, Y. Gao, H. Antoniadis, D. Roitman, W. A. Feld, "Light-Emitting Diodes Based on Poly(p-phenylene vinylenes)", Polym. Mater. Sci. Eng., 75, 323 (1996).

356. V. Choong, Y. Park, Y. Gao, T. Wehrmeister, K. Müllen, B.R. Hsieh, and C. W. Tang, "Dramatic Photoluminescence Quenching of Phenylene Vinylene Oligomer Thin Films upon Submonolayer Ca Deposition," Appl. Phys. Lett. 69, 1492 (1996).

357. Y. Park, E. Ettedgui, V. Choong, Y. Gao, B.R. Hsieh, T. Wehrmeister, and K. Mullen, "Energy Level Bending and Alignment at the Interface between Ca and a Phenylene Vinylene Oligomer," Appl. Phys. Lett. 69, 1080 (1996).

358. Y. Park, V. Choong, Y. Gao, B.R. Hsieh, and C.W. Tang, "Work Function of Indium Tin Oxide Transparent Conductor Measured by Photoelectron Spectroscopy," Appl. Phys. Lett. 68, 2699 (1996).

359. H. Razafitrimo, Y. Gao, and B.R. Hsieh, "A Layer-wise Topographic Study of a Polymeric Light Emitting Diode: Indium Tin Oxide/Poly(diphenyl phenylene vinylene)/Ag," Synth. Met. 79, 103 (1996)

360. B.R. Hsieh, E. Ettedgui, K.T. Park, and Y. Gao, "The Surface Species of Poly(p-phenylene vinylene) and Their Effects on the Metal Interface Formation," Synth. Met. 78, 269 (1996)

361. E. Ettedgui, H. Razafitrimo, Y. Gao, and B.R. Hsieh, "Schottky Barrier Formation at the Ca/Poly(p-phenylene vinylene) Interface and its Role in Tunneling at the Interface," Synth. Met. 78, 247 (1996).

362. C.A. Schmuttenmaer, C.C. Miller, J.W. Herman, J. Cao, D.A. Mantell, Y. Gao, and R.J.D. Miller, "Femtosecond Time-Resolved Photoemission Study of Hot Electron Relaxation at the GaAs(100) Surface," Chem. Phys. 205, 91 (1996).

363. M.R. Robinson, H. Razafitrimo, Y. Gao, and B.R. Hsieh, "The Aging Behaviors of a Sulfonium Precursor Polymer of Poly(p-phenylene vinylene)," Polym. Mater. Sci. Eng. 74, 292 (1996).

364. S. Xu, J. Cao, C. Miller, D.A. Mantell, R.J.D. Miller, and Y. Gao, "Energy Dependence of Electron Lifetime in Graphite Observed with Femtosecond Photoemission Spectroscopy," Phys. Rev. Lett. 76, 483 (1996).

365. E. Ettedgui, H. Razafitrimo, Y. Gao, B.R. Hsieh, W.A. Feld, and M.W. Ruckman, "Evidence for the Formation of Unoccupied States in Poly(2,3-diphenyl phenylene vinylene) Following the Deposition of Metal," Phys. Rev. Lett. 76, 299 (1996).

366. M.A. Aeschlimann, E. Hull, C.A. Schmuttenmaer, J. Cao, Y. Gao, D.A. Mantell, and H.E. Elsayed-Ali, "Time-Resolved Electron Diffraction to Study Photoinduced Molecular Dynamics at Single Crystal Surfaces," Proc. SPIE 2521, 103 (1996).

367. H. Razafitrimo, K. T. Park, E. Ettedgui, Y. Gao, and B. R. Hsieh, "Interface Formation of Ca with Poly(P-Phenylene Alpha,Alpha'-Diphenyl Vinylene) and Poly(P-Phenylene Alpha-Phenylvinylene)." Polymer International 36, 147-153 (1995).

368. Y. Park, E. Ettedgui, Y. Gao, B.R. Hsieh, K. Mullen, "Modeling Band Bending at Metal/PPV Interface Using a Phenylene Vinylene Oligomer," Polym. Preprints, 36(2), 382 (1995).

369. B.R. Hsieh, H. Razafitrimo, Y. Gao, W. A. Feld, "Highly Phenylate Poly(p-phenylene vinylenes) (HP-PPVs) via The Chlorine Precursor Route," Polym. Preprints, 36(2), 85 (1995).

370. B.R. Hsieh, H. Razafitrimo, Y. Gao, W. A. Feld, "Highly Phenylated Poly(p-phenylene vinylenes) (HP-PPVs) via The Chlorine Precursor Route (CPR): On the Photophysical Properties," Polym. Mater. Sci. Eng. 73, 557 (1995).

371. E. Ettedgui, H. Razafitrimo, Y. Gao, and B.R. Hsieh, "Band Bending Modified Tunneling at Metal/Conjugated Polymer Interfaces," Appl. Phys. Lett. 67, 2705 (1995).

372. H. Razafitrimo, E. Ettedgui, L.H. Guo, G.L. McLendon, and Y. Gao, "X-Ray Photoemission Study of the Interface Formation between Ca and Self-Assembled Thiol Monolayers," Appl. Phys. Lett. 67, 2621 (1995).

373. S.P. Duggagupta, L. Tsybeskov, P.M. Fauchet, E. Ettedgui, and Y. Gao, "Post-Anodization Implantation and CVD Techniques for Passibation of Porous Silicon," Microcrytals and Nanocryatalline Semiconductors, Mat. Res. Soc. Symp. Proc. 358, 381 (1995).

374. P.M. Fauchet, C. Peng, L. Tsybeskov, Ju.V. Vandyshev, A. Dubois, L. McLoud, S.P. Duttagupta, J.M. Rehm, G.L. Mclendon, E. Ettedgui, Y. Gao, F. Seiferth, S.K. Kurinec, A. Raisanen, T.E. Orlowski, L.J. Brillson, and G.E. Carver, "Prospects for Light-Emitting Diodes Made of Porous Silicon from Blue to beyond 1.5 m," Proc. SPIE 2144, 98 (1995).

375. M.A. Aeschlimann, C.A. Schmuttenmaer, J. Cao, Y. Gao, H.E. Elsayed-Ali, R.J.D. Miller, and D.A. Mantell, "Observation of Surface Enhanced Multiphoton Photoemission from Metal Surfaces in the Short Pulse Limit," J. Chem. Phys. 102, 8606 (1995).

376. E. Ettedgui, J. Cao, Ken T. Park, Y. Gao, and M.W. Ruckman, "Photo-assisted Oxidation of GaAs(100) with Condensed Water Using Synchrotron Photoemission Spectroscopy," J. Appl. Phys. 77, 5411 (1995).

377. Ken T. Park, Jianming Cao, E. Ettedgui, Y. Gao, and M.W. Ruckman, "Investigation of thin Cr Overlayer in Cr/NH3/GaAs(100) Using Synchrotron Radiation," J. Vac. Sci. Technol. A13, 200 (1995).

378. M.A. Aeschlimann, E. Hull, J. Cao, C.A. Schmuttenmaer, L.G. Jahn, Y. Gao, H.E. Elsayed-Ali, D.A. Mantell, and M.R. Scheinfein, "A Picosecond Electron Gun for Surface Analysis," Rev. Nucl. Instrum. 66, 1000 (1995).

379. E. Ettedgui, H. Razafitrimo, K.T. Park, Y. Gao, and B.R. Hsieh, "X-ray Photoemission Spectroscopy Study of Band Bending at the Interface of Metal with Poly(p-phenylene vinylene)," Surf. Interface Anal. 23, 89 (1995).

380. H. Razafitrimo, K.T. Park, E. Ettedgui, Y. Gao, and B.R. Hsieh, "Interface Formation of Ca with Poly(p-phenylene vinylene)-Di-Phenyl and Poly(p-phenylene vinylene)-Phenyl," Polym. International 36, 147 (1995).

381. C.A. Schmuttenmaer, M. Aeschlimann, J. Cao, Y. Gao, D.A. Mantell, and R.J.D. Miller, "Femtosecond Photoemission Studies of Electron Relaxation at Cu Surfaces," Ultrafast Phenomena IX, A.H. Zewail, G. Mourou, W. Knox, and P.F. Barbara, Eds., 307 (Springer-Verlag, Berlin, 1994).

382. B.R. Hsieh, E. Ettedgui, K.T. Park, and Y. Gao, "The Surface Species of Poly(p-Phenylene-Vinylene) and Their Effects on Calcium Interface Formation," Mol. Cryst. Liq. Cryst. 256, 71 (1994).

383. C.A. Schmuttenmaer, M.A. Aeschlimann, J. Cao, H.E. Elsayed-Ali, R.J.D. Miller, D.A. Mantell, and Y. Gao, "Femtosecond Studies of Carrier Relaxation Processes at Single Crystal Metal Surfaces," Proc. SPIE 2125, 98 (1994).

384. C.A. Schmuttenmaer, M.A. Aeschlimann, J. Cao, H.E. Elsayed-Ali, R.J.D. Miller, D.A. Mantell, and Y. Gao, "Time Resolved Two Photon Photoemission from Cu(100): Energy Dependence of Electron Relaxation," Phys. Rev. B 50, Rapid Comm., 8957 (1994).

385. P.M. Fauchet, C. Peng, L. Tsybeskov, J. Vandyshev, A. Dubois, A. Raisanen, T.E. Orlowski, L.J. Brillson, J.E. Fouquet, S.L. Dexheimer, J.M. Rehm, G.L. Mclendon, E. Ettedgui, Y. Gao, F. Seiferth, and S.K. Kurinec, "Intense Room Temperature Light Emission in Porous Silicon: from Less than 450 nm to beyond 1.5 m," in Advanced Photonics Materials for Information Technology, edited by S. Etemad, 34 (SPIE, 1994).

386. E. Ettedgui, H. Razafitrimo, K.T. Park, Y. Gao, and B.R. Hsieh, "An XPS Study of Sample Preparation on Band Bending at the Interface of Al with Poly(p-phenylene vinylene)," J. Appl. Phys. 75, 7526 (1994).

387. E.A. Murphy, H.E. Elsayed-Ali, Ken T. Park, and Y. Gao, "Temperature-Dependent X-ray Photoelectron Diffraction of Pb(100): Experimental Results and the Single-Scattering Cluster Model," J. Vac. Sci. Technol. A11, 3106 (1993).

388. L. Tsybeskov, C. Peng, S.P. Duttagupta, E. Ettedgui, Y. Gao, P.M. Fauchet, and G.E. Carver, "Comparative Study of Light-Emitting Porous Silicon Anodized with Light Assistance and in the Dark," Mat. Res. Soc. Symp. Proc. 298, 271 (1993).

389. P.M. Fauchet, E. Ettedgui, A. Raisanen, L.J. Brillson, F. Seiferth, S.K. Kurinec, Y. Gao, C. Peng, and L. Tsybeskov, "Can Oxidation and Other Treatments Help Us Understand the Nature of Light-Emitting Porous Silicon?" Mat. Res. Soc. Symp. Proc. 298, 307 (1993).

390. Y. Gao, Ken T. Park, and B.R Hsieh, "Interface Formation of Ca with Poly(p-phenylene vinylene)," J. Appl. Phys. 73, 7894 (1993).

391. Bing R. Hsieh, Y. Gao, and Ken T. Park, "Characteristics of Metal-Poly(phenylene vinylene) Interfaces," in Electroluminescent Materials, Devices, and Large-Screen Displays, edited by E.M. Conwell, M. Stolka, and M.R. Miller, 195 (International Society for Optical Engineering, 1993).

392. E. Ettedgui, C. Peng, L. Tsybeskov, Y. Gao, P.M. Fauchet, H.A. Mizes, and G.E. Carver, "High Spatial Resolution Mapping of Porous Silicon," in Microcrystalline Semiconductor: Material Science and Devices, edited by P.M. Fauchet, C.C. Tsai, L.T. Canham, I. Shimizu, and Y. Aouagi, 173 (Materials Research Society, Pittsburgh, 1993).

393. E. Ettedgui, Ken T. Park, Jianming Cao, Y. Gao, and M.W. Ruckman, "Growth of a Cr Oxide Layer on GaAs(100) by Oxidation with Condensed Water," J. Appl. Phys. 73, 1781 (1993).

394. Ken T. Park and Y. Gao, "Cryogenic Growth of Al Nitride Layers on GaAs(110): X-ray Photoemission and Inverse Photoemission Spectroscopy Studies," Phys. Rev. B 47, 4491 (1993).

395. Y. Gao, Ken T. Park, and B.R. Hsieh, "X-ray Photoemission Investigations of the Interface Formation of Ca and Poly(p-phenylene vinylene)," J. Chem. Phys. 97, 6991 (1992).

396. Y. Gao and Ken T. Park, "Medium Energy Electron Diffraction from Cu(100)," Phys. Rev. B 46, 1743 (1992).

397. T. Balasubramanian, Jianming Cao, and Y. Gao, "X-ray Photoemission Spectroscopy Studies of Cesium and Oxygen on GaAs(100)," J. Vac. Sci. Technol. A 10, 3158 (1992).

398. N. Li, Z. D. Lin, Y. Gao, and J. H. Weaver, "SYNCHROTRON RADIATION PHOTOEMISSION-STUDIES ON THE PALLADIUM COMPOUND SEMICONDUCTOR INTERFACES - VALENCE BAND STUDIES." Vacuum 43, 587-590 (1992).

399. N. Li, Z. D. Lin, Y. Gao, and J. H. Weaver, "VALENCE BAND STUDIES ON Pd/COMPOUND SEMICONDUCTOR INTERFACES." Chinese Physics 11, 987-997 (1991).

400. Ken T. Park, Jianming Cao, Y. Gao, G.W. Wicks, and M.W. Ruckman, "Growth of Al Nitride Layers on GaAs(100) by Reaction with Condensed Ammonia," J. Appl. Phys. 70, 2623 (1991).

401. M.W. Ruckman, M. Strongin, Jianming Cao, Ken T. Park, Y. Gao, and G.W. Wicks, "White Beam Synchrotron Radiation Degradation of GaAs(100)," Appl. Phys. Lett. 59, 849 (1991).

402. E.A. Murphy, H.E. Elsayed-Ali, Ken T. Park, Jianming Cao, and Y. Gao, "Angle Resolved X-ray Photoemission Study of the Surface Disordering of Pb(100)," Phys. Rev. B 43, 12615 (1991).

403. A. Wall, Y. Gao, A. Raisanen, A. Franciosi, and J.R. Chelicowsky, "Electron Density of States of CdTe," Phys. Rev. B 43, 4988 (1991).

404. Y. Gao and Jianming Cao, "Incident Beam Effects in Electron-stimulated Auger Electron Diffraction," Phys. Rev. B 43, 9692 (1991).

405. Y. Gao, C.P. Lusignan, M.W. Ruckman, and M. Strongin, "Growth of Al Oxide Layers on GaAs(100) by Reaction with Condensed Molecular Oxygen," J. Appl. Phys. 67, 7148 (1990).

406. A. Franciosi, A. Wall, Y. Gao, J.H. Weaver, M. H. Tsai, J.D. Dow, R.V. Kasowski, R. Reifenberger, and F. Pool, "d-states, Exchange Splitting, and Mn Electronic Configuration in Cd1-xMnxTe,'' Phys. Rev. B 40, Rapid Comm., 12009 (1989).

407. G.D. Waddill, C.M. Aldao, I.M. Vitomirov, Y. Gao, and J.H. Weaver, "Temperature Effects on Schottky Barrier Formation for Au/InP(110)," J. Vac. Sci. Technol. A 7, 865 (1989).

408. Y. Hu, T.J. Wagener, Y. Gao, and J.H. Weaver, "Empty Electronic State Evolution for Sc and Electron Dynamics at the 3p-3d Giant Dipole Resonance," Phys. Rev. B 39, 8162 (1989).

409. T.J. Wagener, Y. Hu, Y. Gao, M.B. Jost, J.H. Weaver, N.D. Spencer, and K.C. Goretta, "Resonance Inverse Photoemission of Bi2Ca1+xSr2-xCu2O8+y and YBa2Cu3O7-x, Unoccupied Oxygen States, and Plasmons," Phys. Rev. B 39, 2928 (1989).

410. A. Wall, A. Franciosi, Y. Gao, J.H. Weaver, M.-H. Tsai, J.D. Dow, and R.V. Kasowski, "Inverse Photoemission and Resonant Photoemission Characterization of Semimagnetic Semiconductors," J. Vac. Sci. Technol. A 7, 656 (1989).

411. B.M. Trafas, I.M. Vitomirov, C.M. Aldao, Y. Gao, F. Xu, J.H. Weaver, and D.L. Panins, "Cr, Co, Pd, Au, and In Overlayers on PbS(100) Surfaces: Adatom Interactions and Interface Formation," Phys. Rev. B 39, 3265 (1989).

412. Y. Hu, T.J. Wagener, Y. Gao, and J.H. Weaver, "Resonant Inverse Photoemission Involving Transition-metal Subshell Interactions," Phys. Rev. B 38, Rapid Comm. 12708 (1988).

413. I.M. Vitomirov, C.M. Aldao, Zhangda Lin, Y. Gao, B.M. Trafas and J.H. Weaver, "Pd Overlayer Growth on InP(110), GaAs(110), and InSb(110): Comparisons of Anion Surface Segregation," Phys. Rev. B 38, 10776 (1988).

414. H.M. Meyer III, D.M. Hill, T.J. Wagener, Y. Gao, J.H. Weaver, D.W. Capone II, and K.C. Goretta, "Electronic Structures for the YBa2Cu3O6.9 Surface and its Modification by Sputtering and Adatoms of Ti and Cu," Phys. Rev. B 38, 6500 (1988).

415. A. Franciosi, A. Wall, Y. Gao, J.H. Weaver, S. Chang, A. Raisanen, and B. Rehil, "Inverse Photoemission Studies of Ternary Semimagnetic Semiconductors: Where Have All the d-states Gone?" in Proc. 19th Int. Conf. on the Phys. of Semiconductors, edited by W. Zawaolzki and J.M. Langer, (DHN Limited, Warsaw, Poland, 1988).

416. J.H. Weaver, H.M. Meyer III, T.J. Wagener, D.M. Hill, Y. Gao, D. Peterson, Z. Fisk, and A.J. Arko, "Valence Bands, Oxygen in Planes and Chains, and Surface Changes for Single Crystals of M2CuO4 and MBa2Cu3Ox (M=Pr, Nd, Eu, Gd)," Phys. Rev. B 38, 4668 (1988).

417. T.J. Wagener, Y. Gao, I.M. Vitomirov, C.M. Aldao, J.J. Joyce, J.H. Weaver, and C. Capone II, "Disruption, Segregation and Passivation for the Interfaces of Pd and Noble Metal Overlayers on YBa2Cu3O6.9," Phys. Rev. B 38, 232 (1988).

418. Y. Hu, T.J. Wagener, Y. Gao, and J.H. Weaver, "Empty Electronic States of Graphite and the Growth of Au and Pd Clusters," Phys. Rev. B 38, 3037 (1988).

419. Y. Gao, T.J. Wagener, C.M. Aldao, I.M. Vitomirov, J.H. Weaver, and D.W. Capone II, "Photoemission and Inverse Photoemission Studies of La Adatom Interactions with YBa2Cu3O6.9," J. Appl. Phys. 64, 1296 (1988).

420. T.J. Wagener, Y. Gao, H.M. Meyer III, D.M. Hill, S.G. Anderson, and J.H. Weaver "Spectroscopic Examinations of the Surface Stability of High Temperature Superconductors," in Thick Film Processing and Characterization of High Temperature Superconductors, edited by J.M. Happer, R.J. Cotton, and L.C. Feldman, 368 (AIP proceedings of AVS Topical Conference on Thin Film Processing and Characterization of High-Temperature Superconductors, New York, 1988).

421. H.M. Meyer III, Y. Gao, T.J. Wagener, D.M. Hill, S.G. Anderson, and J.H. Weaver, "High Temperature Superconductors: Occupied and Unoccupied Electronic States," in Thick Film Processing and Characterization of High Temperature Superconductors, edited by J.M. Happer, R.J. Cotton, and L.C. Feldman, 254 (AIP proceedings of AVS Topical Conference on Thin Film Processing and Characterization of High-Temperature Superconductors, New York, 1988).

422. Y Gao, H.M. Meyer III, T.J. Wagener, D.M. Hill, S.G. Anderson, and J.H. Weaver "Interface Formation: High Temperature Superconductors with Noble Metals, Reactive Transition Metals, and Semiconductors," in Thick Film Processing and Characterization of High Temperature Superconductors, edited by J.M. Happer, R.J. Cotton, and L.C. Feldman, 358 (AIP proceedings of AVS Topical Conference on Thin Film Processing and Characterization of High-Temperature Superconductors, New York, 1988).

423. Y. Gao, I.M. Vitomirov, C.M. Aldao, T.J. Wagener, J.J. Joyce, C. Capasso, J.H. Weaver, and D.W. Capone II, "Synchrotron Radiation Photoemission Studies of the Interface Formation between Metals and High Tc Superconductors: Al and In on YBa2Cu3O6.9," Phys. Rev. B 37, Rapid Comm., 3741 (1988).

424. B. Smandek, Y. Gao, T.J. Wagener, J.H. Weaver, F. Levy, and G. Margaritondo, "Bremsstrahlung Isochromat Study of the Layered Compounds InSe, TiSe2, SnSe2, SnS2, and Bi2Te3," Phys. Rev. B 37, 4196 (1988).

425. Y. Gao, T.J. Wagener, J.H. Weaver, and D.W. Capone II, "Interface Formation of Semiconductors with High Tc Superconductors: Ge/La1.85Sr0.15CuO4," Phys. Rev. B 37, 515 (1988).

426. D.M. Hill, Y. Gao, H.M. Meyer III, T.J. Wagener, J.H. Weaver, and D.W. Capone II, "Cu-Induced Surface Disruption of La1.85Sr0.15CuO4," Phys. Rev. B 37, 511 (1988).

427. Y. Gao, M. Grioni, B. Smandek, and J.H. Weaver, and T. Tyrie, "Inverse Photoemission Spectrometer for Interface Studies," J. Phys. E 21, 489 (1988).

428. Y. Gao, B. Smandek, M. Nikaido, J.H. Weaver, F. Levy, and G. Margaritondo, "Bremsstrahlung Isochromat Spectroscopy Studies of Conduction Band States in GaSe," Solid State Comm. 65, 11 (1988).

429. H.M. Meyer III, T.J. Wagener, D.M. Hill, Y. Gao, S.G. Anderson, S.D. Krahn, J.H. Weaver, B. Flandermeyer, and D.W. Capone II, "Spectroscopic Evidence for Passivation of the La1.85Sr0.15CuO4 Surface with Gold," Applied Phys. Lett. 51, 1118 (1987).

430. Y. Gao, T.J. Wagener, J.H. Weaver, B. Flandermeyer, and D.W. Capone II, "Reaction and Intermixing at Metal-Superconductor Interfaces: Fe/YBa2Cu3O6.9," Applied Phys. Lett. 51, 1032 (1987).

431. T.J. Wagener, Y. Gao, J.H. Weaver, A.J. Arko, B. Flandermeyer, and D.W. Capone II, "Unoccupied Electronic States and Surface Phenomena for YBa2Cu3O6.9," Phys. Rev. B 36, 3899 (1987).

432. J.H. Weaver, Y. Gao, T.J. Wagener, B. Flandermeyer, and D.W. Capone II, "Reaction and Disruption for Fe/La1.85Sr0.15CuO4: Interface Formation for High Temperature Superconductors," Phys. Rev B 36, Rapid Comm., 3975 (1987).

433. Y. Gao, T.J. Wagener, J.H. Weaver, A.J. Arko, B. Flandermeyer, and D.W. Capone II, "Inverse Photoemission Studies of the Empty Electronic States and Surface Stability of La1.85Sr0.15CuO4," Phys. Rev. B 36, Rapid Comm., 3971(1987).

434. Y. Gao, T.J. Wagener, D.M. Hill, H.M. Meyer III, J.H. Weaver, A.J. Arko, B. Flandermeyer, and D.W. Capone II, "High-Temperature Superconductors: Occupied and Unoccupied Electronic States, Surface Stability, and Interface Formation" in Chemistry of High-Temperature Superconductors, edited by D.L. Nelson, M.S. Whittingham, and T.F. George, 212 (American Chemical Society, Washington DC, 1987).

435. Y. Gao, B. Smandek, T.J. Wagener, J.H. Weaver, F. Levy, and G. Margaritondo, "Bremsstrahlung Isochromat Studies of Conduction Band States in SnS2 and SnSe2," Phys. Rev. B 35, Rapid Comm., 9357 (1987).

436. Y. Gao and R. Reifenberger, "Yield of Photofield Emitted Electrons from Tungsten," Phys. Rev. B 35, 8301(1987).

437. Y. Gao and R. Reifenberger, "Band Structure Effects in Photofield Emission," Phys. Rev. B 35, 6627 (1987).

438. Y. Gao and Reifenberger, "Photofield Emission from Transition Metal Surface States," Phys. Rev. B 35, 4284 (1987).

439. Y. Gao and R. Reifenberger, "Field Emission Energy Distribution Study of Laser Induced Thermal Effects on Metal Surfaces," J. Vac. Sci. Technol. A 4, 1289 (1986).

440. Y. Gao and R. Reifenberger, "Energy Resolved Photofield Emission from the W(100) Surface State," Phys. Rev. B 32, Rapid Comm., 1380 (1985).

441. Y. Gao and R. Reifenberger, "A Design Innovation for the 127° Differential Electron Energy Analyzer," J. Phys. E 18, 381(1985).

442. Y. Gao, K.V. Devi-Prased, and E.W. Prohofsky, "A Self-Consistent Microscopic Theory of Hydrogen Bond Melting with Application to poly(dG)*poly(dC)," J. Chem. Phys. 80, 6291 (1984).

443. Y. Gao and E.W. Prohofsky, "A Modified Self-Consistent Phonon Theory of Hydrogen Bond Melting," J. Chem. Phys. 80, 2242 (1984).

444. W.K. Lee, Y. Gao, and E.W. Prohofsky, "Structure of Hydrated Na ions around a Region of A- or B-DNA Helix," Biopolymers 23, 257 (1984).