Carrier-Phonon Coupling Induced Carrier Localization in All-Inorganic Mixed-Halide Perovskite Micro-hemispheres
Bo-Ting Yang1*, Li-Jyuan Lin1, Chun-Sheng Wu1, Hsu-Cheng Hsu1
1Department of Photonics, National Cheng Kung University, Tainan, Taiwan
* Presenter:Bo-Ting Yang,
All-inorganic mixed-halide perovskites have attracted massive attention because of their stability and the application in optoelectronic device. However, the dynamics of carrier-transport and mechanism of recombination in all-inorganic mixed-halide perovskites have not been completely discussed. Here, we present carrier-phonon coupling induced carrier localization effect in crystalline lattice of CsPbBrxCl3-x micro-hemispheres perovskite (MHSP) measured at room temperature. The CsPbBrxCl3-x MHSP was obtained through vapor-anion-exchange reactions. After modifying the reaction temperature of anion-exchange reaction, we can control the composition of halides in our material. By measuring time-resolved photoluminescence (TRPL) and spectral-dependent TRPL, we found that the replacement of the heavier Br- to the lighter Cl- in CsPbBr3 could enhance the carrier-phonon coupling strength, leading to the formation of the polaron in perovskite. The polaron formation is mainly responsible for prolonging the PL lifetime. This work offers the key for designing high-performance optoelectronic device.

Keywords: all-inorganic perovskite, carrier-phonon coupling, carrier localization, polaron