Real-Time Investigation of Sn(II) Oxidation in Pb-Free Halide Perovskites by X-ray Absorption and Mössbauer Spectroscopy
Document Type
Article
Date of Original Version
5-24-2021
Abstract
Sn(II) halide perovskites are a less toxic alternative to Pb-based materials in perovskite solar cells, but oxidation to Sn(IV) introduces additional degradation pathways. Improving stability requires mechanistic pictures of O2-and H2O-induced degradation and their synergy. We demonstrate that X-ray absorption spectroscopy reports the average valency of the bulk material, allowing oxidation kinetics to be measured from minutes to days. Optical and X-ray diffraction studies demonstrate the challenge of isolating oxidative degradation with techniques lacking element specificity and oxidation state sensitivity. Finally, 119Sn Mössbauer spectroscopy is presented as a lab-based technique capable of providing information on valency and speciation throughout oxidation.
Publication Title, e.g., Journal
ACS Applied Energy Materials
Volume
4
Issue
5
Citation/Publisher Attribution
Smith, Melissa A., Min Chen, Zhenghong Dai, Cali Antolini, Gethmini K. Jayasekara, Srinivas K. Yadavalli, Benjamin J. Reinhart, Nitin P. Padture, and Dugan Hayes. "Real-Time Investigation of Sn(II) Oxidation in Pb-Free Halide Perovskites by X-ray Absorption and Mössbauer Spectroscopy." ACS Applied Energy Materials 4, 5 (2021). doi: 10.1021/acsaem.1c01143.