Physics of perovskites materials and devices

Contact: Jacky EVEN

Halide perovskites are semiconductor crystals whose atomic structure consists of halogen octahedra (typically iodine, bromine, or chlorine) surrounding a metal atom, usually lead (Pb) or tin (Sn). Since the early 2010s, these compounds have emerged as highly promising materials thanks to their exceptional optoelectronic properties, low production cost, and ease of synthesis. In the field of photovoltaics, perovskite-based solar cells have reached efficiencies comparable to those of silicon solar cells, while perovskite/silicon tandem solar cells now achieve record efficiencies of around 34%, representing a potential technological breakthrough for the ecological transition. Perovskites are also widely investigated for light-emitting applications, particularly in the form of quantum dots for the generation of single photons and entangled photon pairs, which are key building blocks for the development of quantum technologies.

The theoretical physics group of the FOTON Institute, led by Jacky Even, has been a pioneer in international research on halide perovskites through its close collaboration with researchers from the ISCR. The group has made numerous landmark contributions to the field, including the identification of the key role of spin–orbit coupling and the elucidation of the fine structure of the excitonic ground state in colloidal quantum dots. The group’s research philosophy is based on the use of a broad range of theoretical approaches, from ab initio simulations (including density functional theory, DFT) to semi-empirical methods (effective-mass models, tight-binding methods, etc.), while maintaining close interactions with experimental research. Long-standing collaborations have been established with leading experimental groups worldwide, including those of Aditya Mohite at Rice University, Mercouri Kanatzidis at Northwestern University, and Maksym Kovalenko at ETH Zurich. This approach has resulted in numerous publications in leading scientific journals, including Nature and Science, and has earned the group international recognition for its contributions to the understanding of the physics of halide perovskites.