(In-)Stability of Tin Halide Perovskites: Ab Initio Molecular Dynamics Simulations of Perovskite/Water Interfaces
Waldemar Kaiser a, Damiano Ricciarelli a b, Edoardo Mosconi a c, Asma A Alothman c, Francesco Ambrosio a d e, Filippo De Angelis a b
a Computational Laboratory for Hybrid/ Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Chimiche “Giulio Natta” (CNR-SCITEC)
b Department of Chemistry, Biology and Biotechnology, University of Perugia, Italy., Via dell' Elce di Sotto, 8, Perugia, Italy
c Chemistry Department, College of Science, King Saud University
d Department of Chemistry and Biology “A. Zambelli”, University of Salerno
e CNST@Polimi, Istituto Italiano di Tecnologia Milano
International Conference on Hybrid and Organic Photovoltaics
Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
València, Spain, 2022 May 19th - 25th
Organizers: Pablo Docampo, Eva Unger and Elizabeth Gibson
Oral, Waldemar Kaiser, presentation 170
DOI: https://doi.org/10.29363/nanoge.hopv.2022.170
Publication date: 20th April 2022

The replacement of lead by tin is potentially the most promising strategy to design efficient, lead-free perovskites for future energy conversion applications [1]. However, current tin halide perovskites (THPs) still suffer under degradation, especially by oxygen or moisture, and show limited efficiencies with respect to the lead-based counterparts [2, 3]. To date, a detailed understanding of the degradation mechanisms of THPs in water environment is still missing.

Ab initio molecular dynamics (AIMD) simulations [4] are presented to unravel atomistic details of THP/water interfaces. We compare MASnI3 with the lead-based counterpart MAPbI3 to assess the impact of the B-site metal on the water-induced degradation mechanism. In addition, we study the interface between DMASnBr3, a water-stable THP recently proposed for photocatalytic hydrogen production [5], and water to understand the origins of its unprecedented water stability and the concomitant impact of the A-site and X-site variation on the THP stability. Our results indicate a facile solvation of surface tin−iodine bonds in MASnI3, while MAPbI3 appears more robust to degradation despite strong hydration of the perovskite surface. Furthermore, AIMD simulations show the formation of amorphous surface layers at the DMASnBr3/water interface, consisting of hydrated zero-dimensional SnBr3 complexes with stable Sn-Br bonds, which protect the inner structure from degradation. This observation, in combination with the higher hydrophobicity of the DMA cation, explains the water stability of DMASnBr3. Based on our results, we discuss potential routes which may assist the design of stable THPs.

We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info