Uncovering the Electron?Phonon Interplay and Dynamical Energy?Dissipation Mechanisms of Hot Carriers in Hybrid Lead Halide Perovskites

The discovery of slow hot carrier cooling in hybrid organic–inorganic lead halide perovskites (HOIPs) has provided exciting prospects for efficient solar cells that can overcome the Shockley–Queisser limit. Questions still loom over how electron-phonon interactions differ from traditional polar semiconductors. Herein, coupling (EPC) strength common perovskite films (MAPbBr3, MAPbI3, CsPbI3, and FAPbBr3) is obtained using transient absorption spectroscopy by analyzing thermodynamics via a simplified two-temperature model. Density function theory calculations are numerically performed at relevant electron-temperatures to confirm experiments. Further, variation carrier-temperature large range carrier-densities HOIPs analyzed, an “S-shaped” dependence initial carrier-density reported. phenomenon attributed dominance polaron screening destabilization effect which causes increasing-decreasing fluctuation temperature low excitation powers; hot-phonon bottleneck effectively increases higher carrier-densities. turning point relationship indicative critical Mott density related nonmetal-metal transition. EPC analysis provides novel perspective quantify energy transfer HOIPs, electron-lattice subsystem, complicated screening-bottleneck interplay comprehensively described, resolving existing experimental contradictions.