报告人：沙威博士 浙江大学 国家“青年千人”
Perovskite solar cells (PSCs) show a great potential to be the next-generation high-performance photovoltaics. Device modeling is essential to understand the device physics and improve the power conversion efficiency of PSCs. Here, I will report our recent progress on the detailed balance analysis and drift-diffusion model for PSCs.
First, the detailed balance theory will be introduced and the difference between the detailed balance model and Shockley diode equation will be discussed. The role of light trapping and non-radiative recombination in device performance will be investigated. Second, the drift-diffusion equation will be connected to the detailed balance theory. The Shockley-Queisser efficiency limit is expected to be approached by the drift-diffusion model through correcting the intrinsic radiative recombination and controlling the contact characteristics of electrodes. The limitation of the traditional Roosbroeck-Shockley expression and the equivalence between the selective electrodes and the device configuration of carrier transport layers are to be clarified. Third, photon recycling of PSCs will be studied by the angular restriction based thought experiments. The external luminescence quantum efficiency is to be investigated under the influence of non-radiative recombination. A reasonable reduction bound of open-circuit voltage (relative to its limiting value) is proposed to evaluate the photon recycling effect. Four, a modified detailed balance model will be built to understand and quantify the efficiency loss of PSCs. The modified model captures the light-absorption dependent short-circuit current, contact and transport-layer modified carrier transport, as well as recombination and photon-recycling influenced open-circuit voltage.
The work contributes to fundamental understanding of device physics of PSCs. The developed model offers a systematic design and analysis tool to photovoltaic science and technology.
Wei E.I. Sha received the B.S. and Ph.D. degrees in Electronic Engineering at Anhui University, Hefei, China, in 2003 and 2008, respectively. From Jul. 2008 to Jul. 2017, he was a Postdoctoral Research Fellow and then a Research Assistant Professor in the Department of Electrical and Electronic Engineering at the University of Hong Kong, Hong Kong. Now, he is an Assistant Professor in the College of Information Science & Electronic Engineering at Zhejiang University, Hangzhou, China.
He has published 90 peer-reviewed journal papers included in Web of Science. His works were widely cited by different academic societies, with the Google Scholar citations of 3340 times. He has contributed 18 invited talks in international conferences, and received four Best Student Paper Prizes and one Young Scientist Award with his students. In 2015, he was awarded Second Prize of Science and Technology from Anhui Province Government, China. In 2017, he was awarded the Marie Skłodowska-Curie Individual Fellowship of European Commission and the Thousand Talents Program for Distinguished Young Scholars of China.
Dr. Sha is an IEEE senior member and an OSA member. He engages in theoretical and computational research in electromagnetics and optics, focusing on the multiphysics and interdisciplinary areas. His research involves fundamental and applied aspects in plasmonics, emerging photovoltaics, metasurfaces, quantum electrodynamics, and computational electromagnetics.