Understanding the charge mobility of lead-halide perovskite materials is crucial for their use in photovoltaic applications. Using X-ray spectroscopic techniques, the structural deformations affecting the charge mobility, which plays a central role in solar energy conversion, have been identified and quantified by an international team of scientists led by Giulia Mancini (at the University of Pavia) and M. Chergui at EPFL.
Lead-halide perovskites' use in photovoltaic applications relies on the generation of charges (electrons and hole) upon absorption of light. These charges migrate through the material to generate an electrical current. One of the crucial physical properties in this respect is the so-called charge mobility. Despite their remarkable performances in light-to-electricity conversion, a limitation of perovskites is their charge mobilities, which are orders of magnitude smaller than those of conventional semi-conductors used in photovoltaics.