Alerts in High-resolution TEM characterization of perovskite material

TL;DR

This paper addresses the common misidentification issues in high-resolution TEM analysis of methylammonium lead iodide perovskite, providing classification, correction methods, and strategies to prevent radiation damage for accurate characterization.

Contribution

It offers a systematic classification and correction of misidentifications in HRTEM of MAPbI3, along with methods for proper phase identification and damage control.

Findings

Misidentifications of PbI2 as perovskite are widespread in HRTEM.

Crystallographic parameters for MAPbI3 and PbI2 are clearly distinguished.

Proposed methods improve accuracy and reduce radiation damage in TEM analysis.

Abstract

High-resolution TEM (HRTEM) is a powerful tool for structure characterization. However, methylammonium lead iodide (MAPbI3) perovskite is highly sensitive to electron beams and easily decompose into lead iodide (PbI2). Universal misidentifications that PbI2 is incorrectly labeled as perovskite are widely exist in HRTEM characterization, which would negatively affect the development of perovskite research field. Here misidentifications in MAPbI3 perovskite calibration are summarized, classified and corrected based on corresponding electron diffraction (ED) simulations. Corresponding crystallographic parameters of intrinsic tetragonal MAPbI3 and the confusable hexagonal PbI2 are also presented clearly. Finally, the method of proper phase identification and some ways to control the radiation damage in HRTEM are provided. This work paves the way to avoid misleadings in HRTEM characterization of perovskite and other electron beam-sensitive materials in the future.