Identifying Reactive Sites and Surface Traps in Chalcopyrite Photocathodes.
- Authors
- Type
- Published Article
- Journal
- Angewandte Chemie International Edition in English
- Publisher
- Wiley (John Wiley & Sons)
- Publication Date
- Oct 25, 2021
- Volume
- 60
- Issue
- 44
- Pages
- 23651–23655
- Identifiers
- DOI: 10.1002/anie.202108994
- PMID: 34428331
- Source
- Medline
- Keywords
- Language
- English
- License
- Unknown
Abstract
Gathering information on the atomic nature of reactive sites and trap states is key to fine tuning catalysis and suppressing deleterious surface voltage losses in photoelectrochemical technologies. Here, spectroelectrochemical and computational methods were combined to investigate a model photocathode from the promising chalcopyrite family: CuIn0.3 Ga0.7 S2 . We found that voltage losses are linked to traps induced by surface Ga and In vacancies, whereas operando Raman spectroscopy revealed that catalysis occurred at Ga, In, and S sites. This study allows establishing a bridge between the chalcopyrite's performance and its surface's chemistry, where avoiding formation of Ga and In vacancies is crucial for achieving high activity. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.