Contact: Olivier PLANTEVIN

Optical Spectroscopy of hybrid perovskite materials

Over the past few years, hybrid organic-inorganic perovskites have become one of the most promising low-cost alternatives to traditional semiconductors in the field of photovoltaics and light emitting devices. It combines both attractive features of organic and inorganic materials within a single composite, for instance with stronger excitonic properties and brighter luminescence. Within these emerging materials, multiple-cation mixed halide perovskites have been highlighted due to their facile band gap tunability by varying the halide composition and improved structural stability.However, even these most advanced absorber materials still suffer from instabilities due to halide ion migration under photoexcitation. We address the origin of these puzzling opto-electronic properties with photoluminescence spectroscopy together with defect engineering through ion irradiation. Point defects modify the electronic and light emitting properties of the material as well as the photo-induced halide mobility which is one of today’s challenge for improved stability in opto-electronic devices. We are also studying advanced perovskite materials infiltrated in mesoporous media developed for solar cell applications in close collaboration with LPICM, Ecole Polytechnique.

S. K. Gautam, M. Kim, D. R. Miquita, J.-E. Bourée, B. Geffroy and O. Plantevin
 Reversible Photo-Induced Phase Segregation and Origin of Long Carrier Lifetime in Mixed-Halide Perovskite Films, Advanced Functional Materials (2020) 2002622