Phonon-driven transient bandgap renormalization in perovskite single crystals
Lijie Wang, Hong Wang, Razan Nughays, Wojciech Ogieglo, Jun Yin, Luis Gutiérrez‐Arzaluz, Xinyuan Zhang, Jianxin Wang, Ingo Pinnau, Osman M. Bakr, Omar F. Mohammed
Abstract
single crystals, as evidenced by asymmetric spectral evolutions and transient reflection spectral shifts in the picosecond timescale. Moreover, we performed a spatiotemporal study upon optical excitation with time-resolved scanning electron microscopy and identified that the surface charge carrier diffusion and transient bandgap renormalization are strongly correlated in time. These findings highlight the need to re-evaluate current theories on photo-induced bandgap renormalization and provide a new approach for precisely controlling the optical and electronic properties of perovskite materials, enabling the design and fabrication of high-performance optoelectronic devices with exceptional efficiency and unique properties.