Assessing the defect tolerance of kesterite-inspired solar absorbers
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Author(s)
Type
Journal Article
Abstract
Various thin-film I2–II–IV–VI4 photovoltaic absorbers derived from kesterite Cu2ZnSn(S,Se)4 have been synthesized, characterized, and theoretically investigated in the past few years. The availability of this homogeneous materials dataset is an opportunity to examine trends in their defect properties and identify criteria to find new defect-tolerant materials in this vast chemical space. We find that substitutions on the Zn site lead to a smooth decrease in band tailing as the ionic radius of the substituting cation increases. Unfortunately, this substitution strategy does not ensure the suppression of deeper defects and non-radiative recombination. Trends across the full dataset suggest that Gaussian and Urbach band tails in kesterite-inspired semiconductors are two separate phenomena caused by two different antisite defect types. Deep Urbach tails are correlated with the calculated band gap narrowing caused by the (2III + IVII) defect cluster. Shallow Gaussian tails are correlated with the energy difference between the kesterite and stannite polymorphs, which points to the role of (III + III) defect clusters involving Group IB and Group IIB atoms swapping across different cation planes. This finding can explain why in-plane cation disorder and band tailing are uncorrelated in kesterites. Our results provide quantitative criteria for discovering new kesterite-inspired photovoltaic materials with low band tailing.
Date Issued
2020-08-25
Date Acceptance
2020-08-25
Citation
Energy & Environmental Science, 2020, 13 (10), pp.3489-3503
ISSN
1754-5692
Publisher
Royal Society of Chemistry (RSC)
Start Page
3489
End Page
3503
Journal / Book Title
Energy & Environmental Science
Volume
13
Issue
10
Copyright Statement
© The Royal Society of Chemistry 2020. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence http://creativecommons.org/licenses/by/3.0/.
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Sponsor
Commission of the European Communities
Identifier
https://pubs.rsc.org/en/content/articlelanding/2020/EE/D0EE02177F#!divAbstract
Grant Number
720907
Subjects
Energy
Publication Status
Published
Date Publish Online
2020-08-25