Infrared optical absorption of Fr?hlich polarons in metal halide perovskites  

作　　者：崔钰 刘晓逸 马旭菲 邓加培 刘怡言 王子武 Yu Cui;Xiao-Yi Liu;Xu-Fei Ma;Jia-Pei Deng;Yi-Yan Liu;Zi-Wu Wang(Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology,Department of Physics,School of Science,Tianjin University,Tianjin 300354,China)

机构地区：[1]Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology,Department of Physics,School of Science,Tianjin University,Tianjin 300354,China

出　　处：《Chinese Physics B》2023年第9期408-413,共6页中国物理B（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.11674241 and 12174283)。

摘　　要：The formation of Frohlich polarons in metal halide perovskites,arising from the charge carrier-longitudinal optical(LO)phonon coupling,has been proposed to explain their exceptional properties,but the effective identification of polarons in these materials is still a challenging task.Herein,we theoretically present the infrared optical absorption of Frohlich polarons based on the Huang-Rhys model.We find that multiphonon overtones appear as the energy of the incident photons matches the multiple LO phonons,wherein the average phonon number of a polaron can be directly evaluated by the order of the strongest overtone.These multiphonon structures sensitively depend on the scale of electronic distribution in the ground state and the dimensionality of the perovskite materials,revealing the effective modulation of competing processes between polaron formation and carrier cooling.Moreover,the order of the strongest overtone shifts to higher ones with temperature,providing a potential proof that the carrier mobility is affected by LO phonon scattering.The present model not only suggests a direct way to verify Frohlich polarons but also enriches our understanding of the properties of polarons in metal halide perovskites.

关 键 词：metal halide perovskites POLARON Huang-Rhys factor 

分 类 号：TB34[一般工业技术—材料科学与工程]