Webinar title: Engineering Ta3N5 Thin Film Photoanode for Efficient Solar Water Splitting
Speaker: Yanbo Li
Webinar time: July 13, 2023 (Thursday) 16:00
Venue: Room 208, New Environmental Building, Tencent Meeting 877-627-725, Password 230713
Inviter: Yuetian Chen, Yixin Zhao
Abstract:
Tantalum nitride (Ta3N5) is a promising photoanode material with a theoretical maximum solar-to-hydrogen conversion efficiency of over 15% for photoelectrochemical water splitting. However, the highest solar conversion efficiency achieved is still far below its theoretical limit. The presence of deep-level defects in the bulk and at the interfaces is probably the major limiting factor of the efficiency of Ta3N5 photoanode. In the past few years, our group has been devoted to improving the efficiency of Ta3N5 thin film photoanode via band structure engineering, defect engineering, interface engineering, and co-catalyst modification. By constructing a gradient band structure in the bulk of Ta3N5 thin film through gradient Mg-doping, we achieved a half-cell solar-to-hydrogen conversion efficiency (HC-STH) of 3.31% thanks to the improved bulk charge separation efficiency in the gradient Mg-doped Ta3N5 photoanode. Alternatively, by modifying the interfaces of Ta3N5 thin film with an electron transport layer (ETL: In-doped GaN) and a hole transport layer (HTL: Mg-doped GaN), we realized a heterostructure Ta3N5 photoanode with an HC-STH of 3.46%. Lately, we demonstrated a heterogeneous doping strategy that combined surface La doping with bulk gradient Mg doping in Ta3N5 thin film to decouple light absorption and carrier transport, resulting in a record-high HC-STH of 4.07% for Ta3N5 photoanode, ten times higher than what we achieved a decade ago. These results established Ta3N5 as a leading performer among visible‐light‐responsive photoanodes for PEC water splitting.
About the speaker:
Prof. Yanbo Li is currently with the Institute of Fundamental and Frontier Science at the University of Electronic Science and Technology of China (UESTC). He obtained his Bachelor (2005) and Master (2007) degrees in Physics from Shanghai Jiao Tong University and his Ph.D. degree (2010) in Engineering Synthesis from The University of Tokyo (UT). He then worked as a Postdoc Fellow in Kazunari Domen’s group at UT (2010-2014) and in Joint Center for Artificial Photosynthesis (JCAP) at Lawrence Berkeley National Lab (2014-2016). Since starting his independent research in 2016 at UESTC, his group has been devoted to developing efficient Ta3N5 thin film photoanode for photoelectrochemical water splitting. In the past few years, he has published more than 40 papers as the first/corresponding author, including Nature Catalysis, Nature Communications (5), Angewandte Chemie, Advanced Materials, Advanced Functional Materials, Energy & Environmental Science, Nano Letters (2), ACS Energy Letters (2), and ACS Catalysis (3). His research has been funded by the National Talent Recruiting Program, National Natural Science Foundation of China (2), and Sichuan “Tianfu Emei Plan”. He has served as the Associate Editor of Nanoscale Research Letters (2018-2022) and Journal of Electronic Science and Technology (2018-now). He had been awarded Chinese Government Award for Outstanding Self-Financed Students Abroad (2009), JSPS Postdoc Fellowship (2010), Award for Excellence in Ph.D. Thesis at UT (2011), CSC-Jingbo Award for Excellence in Ph.D. Thesis Advisor (2021), etc.