Free and self-trapped exciton emission in perovskite CsPbBr3 microcrystals

Fang Pan; Jinrui Li; Xiaoman Ma; Yang Nie; Beichen Liu; Honggang Ye

doi:10.1039/d1ra08629d

Free and self-trapped exciton emission in perovskite CsPbBr₃ microcrystals

RSC Adv. 2022 Jan 5;12(2):1035-1042. doi: 10.1039/d1ra08629d. eCollection 2021 Dec 22.

Authors

Fang Pan¹, Jinrui Li², Xiaoman Ma³, Yang Nie¹, Beichen Liu¹, Honggang Ye¹

Affiliations

¹ Department of Applied Physics, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University Xi'an 710049 People's Republic of China hgye@mail.xjtu.edu.cn.
² Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, School of Electronic Science and Engineering, Xi'an Jiaotong University Xi'an 710049 People's Republic of China.
³ School of Physical Science and Technology, Xinjiang University Urumqi 830046 People's Republic of China.

Abstract

The all-inorganic perovskite CsPbBr₃ has been capturing extensive attention due to its high quantum yield in luminescence devices and relatively high stability. Its luminescence is dominated by free exciton (FE) recombination but additional emission peaks were also commonly observed. In this work, a CsPbBr₃ microcrystal sample in the orthorhombic phase was prepared by the chemical vapor deposition method. In addition to the FE peak, a broad emission peak was found in this sample and it was attributed to self-trapped excitons (STEs) based on its photophysical properties. The STE emission can only be observed below 70 K. The derived Huang-Rhys factor is ∼12 and the corresponding phonon energy is 15.3 meV. Its lifetime is 123 ns at 10 K, much longer than that of FE emission. The STE emission is thought to be an intrinsic property of CsPbBr₃.