Real-Time Investigation of Sn(II) Oxidation in Pb-Free Halide Perovskites by X-ray Absorption and Mössbauer Spectroscopy

Authors

Melissa A. Smith, University of Rhode Island
Min Chen, Brown University
Zhenghong Dai, Brown University
Cali Antolini, University of Rhode Island
Gethmini K. Jayasekara, University of Rhode Island
Srinivas K. Yadavalli, Brown University
Benjamin J. Reinhart, Argonne National Laboratory
Nitin P. Padture, Brown University
Dugan Hayes, University of Rhode IslandFollow

Document Type

Article

Date of Original Version

5-24-2021

Department

Chemistry

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

Melissa A. Smith, 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), 4327-4332 (2021). DOI: 10.1021/acsaem.1c01143.

Available at: https://doi.org/10.1021/acsaem.1c01143