Polarization-resolved surface and bulk states in CsPbBr3 single crystals via second harmonic generation
Abstract
Due to their superior electronic and optical properties, halide perovskite single crystals have been potential candidates for developing high-efficiency optoelectronic devices. Defect states located on the surface or within the bulk of single crystals play a crucial role in determining the performance of devices. In this work, the surface and bulk states in CsPbBr3 single crystals were investigated by polarization-resolved second harmonic generation (SHG) measurements. Onefold anisotropy of SHG intensity indicates that the polycrystalline Cs4PbBr6 and CsPb2Br5 phases dominate the surface, which exhibits Cs symmetry. Moreover, an unpolarized and strong luminescence was observed induced by two-photon absorption, which displays a twofold symmetry. Br vacancies within the bulk were identified as the radiative recombination centers according to their energy level position. These experimental results not only establish a method for distinguishing between surface and bulk states but also facilitate a deeper understanding of the optical properties of defect states in CsPbBr3 single crystals.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (9)
Shixiong Zhang
Weizhi Yu
College of Physics and Electronic Science, Hubei Key Laboratory of Photoelectric Materials and Devices, Hubei Engineering Research Center for Micro-Nano Optoelectronic Devices and Integration, Hubei Normal University 1 , Huangshi 435002,
Junkang Wu
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Nano-optoelectronics Frontier Center of Ministry of Education, School of Physics, Peking University 1 , Beijing 100871,
Yingming Song
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 2 , Beijing 100871,
Ruiming Li
Hongri Liu
College of Physics and Electronic Science, Hubei Key Laboratory of Photoelectric Materials and Devices, Hubei Engineering Research Center for Micro-Nano Optoelectronic Devices and Integration, Hubei Normal University 1 , Huangshi 435002,
Meifeng Liu
College of Physics and Electronic Science, Hubei Key Laboratory of Photoelectric Materials and Devices, Hubei Engineering Research Center for Micro-Nano Optoelectronic Devices and Integration, Hubei Normal University 1 , Huangshi 435002,
Weikun Ge
Ning Tang