Physical Chemistry Seminar: Professor David Reichman, Columbia University (Host: Tom Markland)
"Charge Transport in Lead-Halide Perovskites"
About the Seminar
Over the last decade lead halide perovskites have emerged as a new class of solar cell materials. In a practical sense what is most remarkable about these systems is that they manifest extremely high photovoltaic efficiencies even when fabricated by rapid and inexpensive solution phase growth methods. I will detail several puzzling physical features of these perovskites, which include long diffusion lengths despite modest charge mobility and very sharp absorption characteristics despite large dynamical (and presumably) static disorder. Next I will present a theoretical approach that resolves these puzzles. Time permitting I will briefly describe a completely distinct class of materials that also often is found in the form of a perovskite structure: high temperature superconducting ceramic materials. A detailed theoretical consensus on the nature of the unusual magnetic and electronic properties of these materials is lacking, despite 3 decades of intense focus. Although I will shed no new light on these materials, I will outline a novel ab initio electronic structure approach that has the capability to do so.