Speakers

Prof. Yanfa YAN is a Distinguished University Professor in the Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization at The University of Toledo. He holds the Ohio Research Scholar Endowed Chair, since 2011. Previously, he was a Principal Scientist at the National Renewable Energy Laboratory. His expertise includes thin-film solar cell fabrication, defect physics of semiconductors, and nanoscale characterization of microstructures, interfaces, and defects in thin-film photovoltaic materials. He is a Fellow of the American Physical Society.

From Lead Halide Perovskites to Lead-Free Metal Halide Perovskites and Perovskite Derivatives

Abstract

Lead (Pb) halide perovskites have attracted great attention in photovoltaic (PV) and light-emitting diode (LED) applications due to their outstanding optoelectronic and defect properties.   Despite the exciting progress on device performance, the commercialization of these emerging technologies still face significant challenges, one of which is the inclusion of toxic Pb. Searching for Pb-free perovskite solar cell absorbers has been an attractive research direction. In this presentation, we discuss the approaches for Pb replacement and their consequences. We will report on the theoretical understanding of the electronic, optical, and defect properties of Pb and Pb-free halide perovskites and perovskite derivatives as well as the experimental results available in the literature. The theoretical understanding explains well why Pb halide perovskites exhibit superior photovoltaic properties, but Pb-free perovskites and perovskite derivatives do not. The application of Pb-free perovskites in LED applications will also be discussed.