Real‐Time In Situ Observation of Microstructural Change in Organometal Halide Perovskite Induced by Thermal Degradation. (2nd September 2018)

• Record Type: Journal Article
• Authors: Kim, Tae Woong; Shibayama, Naoyuki; Cojocaru, Ludmila; Uchida, Satoshi; Kondo, Takashi; Segawa, Hiroshi
• Is Part Of: Advanced functional materials. Volume 28:Number 42(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-09-02
• Subjects: organometal halide perovskite -- solar cells -- thermal degradation -- transmission electron microscopy; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201804039
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Organometal halide perovskites have demonstrated remarkable achievements in solar cell applications and have attracted tremendous attention as next‐generation photovoltaic materials. Regardless of the unprecedented success, the degradation of the perovskite has caused the performance of the perovskite solar cells to be unreliable and prevented their commercialization. However, the detailed degradation mechanism of the perovskite has yet to be elucidated. In this study, the entire procedure of the thermally induced degradation of methylammonium lead iodide (MAPbI3 ) is reported using real‐time in situ transmission electron microscopy. The in situ investigation directly illustrates the detailed process of precipitating trigonal PbI2 grains during thermal degradation and confirms that trigonal PbI2 is precipitated from the amorphized MAPbI3 layer via intermediate states. The intermediate states and their stackings enable the generation of 3D linear‐empty spaces that can be utilized as passages by elements during the decomposition and intercalation of the perovskite. This report will provide critical clues for the commercialization of the perovskite‐based solar cells and for further investigation of the synthesis of the perovskite, which is not fully understood. Abstract : The whole procedure of thermal degradation of organometal halide perovskite (MAPbI3 ) by using real‐time in situ transmission electron microscopy is reported. In this study, it is confirmed that the thermal degradation induces precipitation of trigonal PbI2 grains from the amorphized MAPbI3 via intermediate states and the intermediate states can be utilized as paths during decomposition and synthesis of the organometal halide perovskite.