Auger Electron Spectroscopy Analysis of the Thermally Induced Degradation of MAPbI3 Perovskite Films

Wei-Chun Lin; Wei-Chun Lo; Jun-Xian Li; Pei-Chen Huang; Man-Ying Wang

doi:10.1021/acsomega.1c05002

Auger Electron Spectroscopy Analysis of the Thermally Induced Degradation of MAPbI₃ Perovskite Films

ACS Omega. 2021 Nov 29;6(50):34606-34614. doi: 10.1021/acsomega.1c05002. eCollection 2021 Dec 21.

Authors

Wei-Chun Lin^{1

2}, Wei-Chun Lo^{1

2}, Jun-Xian Li^{1

2}, Pei-Chen Huang¹, Man-Ying Wang¹

Affiliations

¹ Department of Photonics, National Sun Yat-Sen University, No. 70, Lianhai Rd., Gushan Dist., Kaohsiung City 804, Taiwan (ROC).
² Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhua Rd., Xitun Dist., Taichung City 407802, Taiwan (ROC).

Abstract

Organometal halide perovskites are highly promising materials for photovoltaic applications due to the rapid growth of power conversion efficiency in recent years. However, thermal stability is still a major hurdle for perovskite solar cells toward commercialization. Herein, we first explore the slow thermal response of the CH₃NH₃PbI₃ perovskite crystal investigated via Auger electron spectroscopy (AES). AES image mapping directly observes the evolution of morphology and elemental distribution over time. The AES small spot analysis demonstrates the precise initial degradation position of perovskite with both information regarding physical changes in crystals and chemical changes in elemental bonding at the nanometer scale. X-ray photoelectron spectroscopy (XPS) was used to confirm the surface chemical bonding and composition of the perovskite crystals. This work provides the first insights into the physical and chemical changes of perovskites investigated by AES upon long-term exposure to heat under ambient conditions.