Narrative CV

Yuh-Jen Cheng is currently an associate research fellow at RCAS, Academia Sinica. He received a doctorate degree from the Department of Applied Physics at, Stanford University. His research interests span various areas, including III-nitride semiconductor growth, III-nitride LEDs and lasers in the past, and more recently, 2D material growth and photonic devices, and photoelectrochemical water splitting and electrocatalyst.

TMD semiconductor materials have self-terminating atomic surface structure with strong light interaction and excellent charge transport properties, making it a promising material for atomic scale electronic and photonic devices. The realization of such applications relies on the development of wafer scale crystal growth. Such growth has been challenging due to the weak van der Waals interaction with substrate that results in random nucleation orientation. My work studies the 2D material grow mechanism and have developed growth conditions to achieve aligned nucleation orientation guided by substrate lattice, which paves the way for large scale crystal growth.

Water splitting is an attractive approach to generate green hydrogen from renewable energy. Its success highly depends on the development of electrocatalyst. Noble metal-based materials have been well known for their high efficiency. However, the high-cost limits practical use. My research has developed a transition metal composition and a sonochemical synthesis method to fabricate highly active electrocatalysts for water splitting with very low overpotential compatible with Pt/C.

Education

• Ph.D. in Applied Physics, Stanford University, 1997.
• M. S. in Institue of Optics, University of Rochester, 1990.

Positions and Career

• Associate Research Fellow, Academia Sinica, 2012-present
• Assistant Research Fellow, Academia Sinica, 2008-2012
• Associate Research Technical Staff, Academia Sinica, 2006-2007
• Staff Optical Engineer/project lead, Bookham Technologies, 2000-2005
• Senior Engineer, Seagate Technology, 1997-2000

Selected Publications

• Pei-Xuan Long, Yung-Yu Lai1, Pei-Hao Kang, Chi-Huang Chuang and Yuh-Jen Cheng*, "High photoresponsivity MoS2 phototransistor through enhanced hole trapping HfO₂ gate dielectric", Nanotechnology 35, 025204 (2024).
• Chi-Huang Chuang, Pei-Hao Kang, Yung-Yu Lai, Cheng-Hung Hou, Wei-Che Tseng, Yan-Jia Huang, Mu-Huai Fang, Jing-Jong Shyue, Chao-Cheng Kaun, and Yuh-Jen Cheng*, “Highly Active NiO-Ni(OH)2-Cr2O3/Ni Hydrogen Evolution Electrocatalyst through Synergistic Reaction Kinetics”, ChemSusChem 2023, e202300820.
• Chi-Huang Chuang, Pei-Hao Kang, Yung-Yu Lai, Cheng-Hung Hou, and Yuh-Jen Cheng*, “Junction Engineering in Si Photoanode for Efficient Photoelectrochemical Water Splitting,” ACS Appl. Energy Mater. 2022, 5, 7, 8483–8491 (2022).
• Yung-Yu Lai, Chi-Huang Chuang, Yen-Wei Yeh, Cheng-Hung Hou, Shih-Chieh Hsu, Yi Chou, Yi-Chia Chou, Hao-Chung Kuo, YewChung Sermon Wu, and Yuh-Jen Cheng*, “Substrate Lattice Guided MoS2 Crystal Growth: Implications for van der Waals epitaxy”, ACS Appl. Nano Mater. 4, 4930–4938 (2021).
• Yung-Yu Lai, Yen-Wei Yeh, An-Jye Tzou, Yi-Yuan Chen, YewChung Sermon Wu, Yuh-Jen Cheng*, and Hao-Chung Kuo*, “Dependence of Photoresponsivity and On/Off Ratio on Quantum Dot Density in Quantum Dot Sensitized MoS₂ Photodetector”, Nanomaterials 2020, 10, 1828.