IMX Colloquium - Metal Halide Perovskites for Photovoltaic Applications

Organic-inorganic metal halide perovskites have emerged as attractive materials for solar cells with power-conversion efficiencies now exceeding 26%. This seminar will unravel the fundamental science governing these materials as efficient light-harvesters and charge collectors, examining e.g. fundamental mechanisms underpinning charge-carrier mobility and recombination. Our analysis of intrinsic photophysical parameters opens the promise of targeted material design for solar energy harvesting, based on readily accessible parameters, such as band structure, phonon frequencies and the dielectric function. A range of remaining challenges and opportunities relating to material microstructure, ionic migration and toxicity are further discussed. For example, we have examined how the optoelectronic properties of hybrid perovskites are governed by their nanostructure and structural phases. In the context of silicon-perovskite tandem cells, an important current focus is on discovering the peculiar mechanisms causing detrimental halide segregation in mixed iodide-bromide lead perovskites with desirable electronic band gaps near 1.8eV. Finally, the challenges and rewards of discovering and developing new lead-free perovskites and their structural derivatives are outlined.

Bio: Laura Herz is a Professor of Physics at the University of Oxford and an EPSRC Open Fellow. She received her PhD in Physics from the University of Cambridge in 2002 and was a Research Fellow at St John's College Cambridge from 2001 - 2003. Her current research interests lie in the area of organic, inorganic and hybrid semiconductors, with a strong current focus on advanced materials for solar energy conversion. Her research has been recognized by several awards, including the Michael Faraday Medal by the Institute of Physics, the Environment, Sustainability and Energy Division Award of the Royal Society of Chemistry, the Nevill Mott Medal of the Institute of Physics and the Bessel Award from the Alexander von Humboldt Foundation. She has been listed by Clarivate Analytics as a Highly Cited Researcher since 2018. Laura is a Fellow of the Royal Society, the Royal Society of Chemistry, the Materials Research Society, and the Institute of Physics.