2014.01-present: Professor, Department of Applied Physics, University of Science and Technology Beijing (USTB), China; 2009.03-2014. 01: Professor, Institute of Suzhou Nano-Technology and Nano-Bionics, Chinese Academy of Sciences (CAS), China; 2008.01-2009. 03: Postdoctoral Position, Common Lab of Advanced Industry Technology & Precision Processing, National Chung Hsing University, Taiwan; 2006.07-2008. 01: Research Associate, Department of Physics, Universidad Técnica Federico Santa María, Valparaíso, Chile; 2006.01-2006. 07: Associate Professor, College of Mechanical Engineering and Applied Electronics Technology, China University of Petrol- Beijing; 2004.01-2006. 01: Application Scientist & Application Training, Twinson International Limited, Beijing office; Nanofilm, DRE, STOE, and ISIS GmbH, Germany; 2002.07-2003. 12: Postdoctoral Position, Institute of Physics, Chinese Academy of Sciences, China; 1999. 9-2002. 06: PhD, Institute of Semiconductors, State Key Lab for Integrated Optoelectronics, Chinese Academy of Sciences, China;

1. I have improved the crystal quality of gallium nitride (GaN) thin films on sapphire from a 350°C low-temperature plasma-enhanced atomic layer deposition process (PE-ALD) using an in-situ bake and plasma substrate pretreatment. The achievement was reported as a development of microelectronics news by Semiconductor Today. 2. High quality group III-nitrides via PE-ALD have been further evidenced by employing them into perovskite and quantum dot solar cells which are improved in the aspects of interface enhancement. 3. I have achieved high-performance InGaN/GaN double heterojunction photovoltaic cells with open-circuit voltage of around 2.1 eV and fill factor up to 81% under standard AM 1.5 condition. The results are frequently cited by the community, including the Noble Laureate. 4. The twist angle of mosaic spread and lattice constants of gallium nitride films are innovatively characterized using high-resolution x-ray diffraction method. The community highly admits the practical use and the simplicity, as well as uses this developed method to extend its applications into other films.

One PhD student and 2-3 Master students per year

1. S. Liu, G. Zhao, Y. He, H. Wei, Y. Li, P. Qiu, Y. Song, X. Wang, X. Wang, J. Cheng, M. Peng, F. Zaera and X. Zheng*, Baking and Plasma Pretreatment of Sapphire Surfaces as a Way to Facilitate the Epitaxial Plasma-Enhanced Atomic Layer Deposition Growth of GaN Thin Films, Appl. Phys. Lett., 2020, 116(21), 211601. 2. H. Wei, P. Qiu, Y. He, S. Liu, M. Li, Y. Song, Y. An, M. Peng, and X. Zheng*, Interface modification for high-efficient quantum dot sensitized solar cells using ultrathin aluminum nitride coating, Appl. Surf. Sci., 2019, 1 (476), 608-614. 3. P. Qiu, H. Wei, Y. He, S. Liu, M. Li, Y. Song, Y. An, M. Peng, and X. Zheng*, Growth and Properties of GaN Thin-Film via Atomic Layer Deposition on Fluorine-Doped Tin Oxide Glass Substrate, Ceramics International, 2020, 46, 5765–5772. 4. Z. J. Shang; X. H. Zheng*; C. Yang; Y; Chen; B. Li; L. Sun; Z. Tang and D. G. Zhao, Carrier thermalization under stimulated emission in In0.17Ga0.83N epilayer at room temperature, Appl. Phys. Lett., 2014, 105, 232104. 5. X. Zheng, R. Horng, D. Wuu, M. Chu, W. Liao, M. Wu, R. and Y. Lu, High-quality InGaN/GaN heterojunctions and their photovoltaic effects, Appl. Phys. Lett. 2008, 93, 261108.