Alanazi, T.I., Game, O.S. orcid.org/0000-0002-5573-3602, Smith, J.A. orcid.org/0000-0001-6889-4408 et al. (6 more authors) (2020) Potassium iodide reduces the stability of triple-cation perovskite solar cells. RSC Advances, 10 (66). pp. 40341-40350. ISSN 2046-2069
Abstract
The addition of alkali metal halides to hybrid perovskite materials can significantly impact their crystallisation and hence their performance when used in solar cell devices. Previous work on the use of potassium iodide (KI) in active layers to passivate defects in triple-cation mixed-halide perovskites has been shown to enhance their luminescence efficiency and reduce current–voltage hysteresis. However, the operational stability of KI passivated perovskite solar cells under ambient conditions remains largely unexplored. By investigating perovskite solar cell performance with SnO2 or TiO2 electron transport layers (ETL), we propose that defect passivation using KI is highly sensitive to the composition of the perovskite–ETL interface. We reconfirm findings from previous reports that KI preferentially interacts with bromide ions in mixed-halide perovskites, and – at concentrations >5 mol% in the precursor solution – modifies the primary absorber composition as well as leading to the phase segregation of an undesirable secondary non-perovskite phase (KBr) at high KI concentration. Importantly, by studying both material and device stability under continuous illumination and bias under ambient/high-humidity conditions, we show that this secondary phase becomes a favourable degradation product, and that devices incorporating KI have reduced stability.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 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/) |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/S009213/1 Science and Technology Facilities Council ST/R002754/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 11 Dec 2020 14:10 |
Last Modified: | 11 Dec 2020 14:10 |
Status: | Published |
Publisher: | Royal Society of Chemistry (RSC) |
Refereed: | Yes |
Identification Number: | 10.1039/d0ra07107b |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:168802 |