Solution-Processable Cu3BiS3 Thin Films: Growth Process Insights and Increased Charge Generation Properties by Interface Modification

Thomas Rath; Jose M Marin-Beloqui; Xinyu Bai; Astrid-Caroline Knall; Marco Sigl; Fernando G Warchomicka; Thomas Griesser; Heinz Amenitsch; Saif A Haque

doi:10.1021/acsami.3c10297

Solution-Processable Cu₃BiS₃ Thin Films: Growth Process Insights and Increased Charge Generation Properties by Interface Modification

ACS Appl Mater Interfaces. 2023 Sep 6;15(35):41624-41633. doi: 10.1021/acsami.3c10297. Epub 2023 Aug 25.

Authors

Thomas Rath^{1

2}, Jose M Marin-Beloqui¹, Xinyu Bai¹, Astrid-Caroline Knall², Marco Sigl², Fernando G Warchomicka³, Thomas Griesser⁴, Heinz Amenitsch⁵, Saif A Haque¹

Affiliations

¹ Department of Chemistry, Imperial College London, Molecular Sciences Research Hub White City Campus, Wood Lane, London W12 0BZ, U.K.
² Institute for Chemistry and Technology of Materials, NAWI Graz, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.
³ Institute of Materials Science, Joining and Forming, Graz University of Technology, Kopernikusgasse 24, 8010 Graz, Austria.
⁴ Institute of Chemistry of Polymeric Materials, Montanuniveristät Leoben, Otto Glöckelstrasse 2, 8700 Leoben, Austria.
⁵ Institute of Inorganic Chemistry, NAWI Graz, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.

Abstract

Cu₃BiS₃ thin films are fabricated via spin coating of precursor solutions containing copper and bismuth xanthates onto planar glass substrates or mesoporous metal oxide scaffolds followed by annealing at 300 °C to convert the metal xanthates into copper bismuth sulfide. Detailed insights into the film formation are gained from time-resolved simultaneous small and wide angle X-ray scattering measurements. The Cu₃BiS₃ films show a high absorption coefficient and a band gap of 1.55 eV, which makes them attractive for application in photovoltaic devices. Transient absorption spectroscopic measurements reveal that charge generation yields in mesoporous TiO₂/Cu₃BiS₃ heterojunctions can be significantly improved by the introduction of an In₂S₃ interlayer, and long-lived charge carriers (t_50% of 10 μs) are found.

Keywords: X-ray scattering; interface; metal sulfides; precursor chemistry; transient absorption spectroscopy.