Transmission electron microscopy of organic-inorganic hybrid perovskites: myths and truths

Shulin Chen; Ying Zhang; Jinjin Zhao; Zhou Mi; Jingmin Zhang; Jian Cao; Jicai Feng; Guanglei Zhang; Junlei Qi; Jiangyu Li; Peng Gao

doi:10.1016/j.scib.2020.05.020

Transmission electron microscopy of organic-inorganic hybrid perovskites: myths and truths

Sci Bull (Beijing). 2020 Oct 15;65(19):1643-1649. doi: 10.1016/j.scib.2020.05.020. Epub 2020 May 23.

Authors

Shulin Chen¹, Ying Zhang², Jinjin Zhao³, Zhou Mi², Jingmin Zhang⁴, Jian Cao⁵, Jicai Feng⁵, Guanglei Zhang², Junlei Qi⁶, Jiangyu Li⁷, Peng Gao⁸

Affiliations

¹ Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China; State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China.
² School of Materials Science and Engineering, School of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
³ School of Materials Science and Engineering, School of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China. Electronic address: jinjinzhao2012@163.com.
⁴ Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China.
⁵ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China.
⁶ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China. Electronic address: jlqi@hit.edu.cn.
⁷ Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China. Electronic address: jy.li1@siat.ac.cn.
⁸ Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China; International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China. Electronic address: p-gao@pku.edu.cn.

PMID: 36659040
DOI: 10.1016/j.scib.2020.05.020

Abstract

Organic-inorganic hybrid perovskites (OIHPs) have attracted extensive research interest as a promising candidate for efficient and inexpensive solar cells. Transmission electron microscopy (TEM) characterizations that can benefit the fundamental understanding and the degradation mechanism are widely used for these materials. However, their sensitivity to the electron beam illumination and hence structural instabilities usually prevent us from obtaining the intrinsic information or even lead to significant artifacts. Here, we systematically investigate the structural degradation behaviors under different experimental factors to reveal the optimized conditions for TEM characterizations of OIHPs by using low-dose electron diffraction and imaging techniques. We find that a low temperature (-180 °C) does not slow down the beam damage but instead induces a rapid amorphization for OIHPs. Moreover, a less severe damage is observed at a higher accelerating voltage. The beam-sensitivity is found to be facet-dependent that a (1 0 0) exposed CH₃NH₃PbI₃ (MAPbI₃) surface is more stable than a (0 0 1) surface. With these guidance, we successfully acquire the atomic structure of pristine MAPbI₃ and identify the characterization window that is very narrow. These findings are helpful to guide future electron microscopy characterizations of these beam-sensitive materials, which are also useful for finding strategies to improve the stability and performance of the perovskite solar cells.

Keywords: Atomic structure CH(3)NH(3)PbI(3); Beam damage mechanism; Facet dependency; Organic-inorganic hybrid perovskites; Transmission electron microscopy.