Emmanuelle DELEPORTE (LuMIn, Université Paris-Saclay, ENS Paris-Saclay, CentraleSupélec, CNRS, 91 190 Gif-sur-Yvette)

Molecular crystals based on organic-inorganic halide perovskites (also named hybrid perovskites) of general formula (RNH₃)₂(CH₃NH₃)_n-1Pb_nX_3n+1 where R is an organic group and X a halogen are a new class of semiconductors exhibiting fabulous optical properties. Indeed, the development of solar cells containing hybrid perovskites as the light-absorbing material has undergone an extremely rapid development, achieving record efficiencies as high as 25,7% in 2023 and hybrid perovskites now appear to be ideal materials for Si/perovskite tandem cells, which extremely rapid efficiency progresses (the most recent record: 32,5% in 2023). In addition to photovoltaic applications, hybrid perovskites reveal also relevant in the field of light emission (LEDs, lasers). Finally, it is important to highlight that these semiconductors are solution-processed, promising low-cost and large surface devices.  

  This spectacular success is due to the fact that organic-inorganic halide perovskites possess remarkable optical and electronic properties, combining the advantages of organic and inorganic semiconductors but also showing completely original and specific properties. In particular, hybrid perovskites show interesting excitonic properties which can be tuned by varying the composition of the molecules. Using continuous and time-resolved micro-photoluminescence spectroscopy, we will explore the intrinsic properties of excitons in hybrid perovskites, in the context of both photovoltaics and lasers.

Contact : Sylvie.Begin@ipcms.unistra.fr