Strong absorption and ultrafast localisation in NaBiS2 nanocrystals with slow charge-carrier recombination
Abstract
I-V-VI2 ternary chalcogenides are gaining attention as earth-abundant, nontoxic, and air-stable absorbers for photovoltaic applications. However, the semiconductors explored thus far have slowly-rising absorption onsets, and their charge-carrier transport is not well understood yet. Herein, we investigate cation-disordered NaBiS2 nanocrystals, which have a steep absorption onset, with absorption coefficients reaching >105 cm−1 just above its pseudo-direct bandgap of 1.4 eV. Surprisingly, we also observe an ultrafast (picosecond-time scale) photoconductivity decay and long-lived charge-carrier population persisting for over one microsecond in NaBiS2 nanocrystals. These unusual features arise because of the localised, non-bonding S p character of the upper valence band, which leads to a high density of electronic states at the band edges, ultrafast localisation of spatially-separated electrons and holes, as well as the slow decay of trapped holes. This work reveals the critical role of cation disorder in these systems on both absorption characteristics and charge-carrier kinetics.
Main Authors
Format
Articles
Research article
Published
2022
Series
Subjects
Publication in research information system
Publisher
Nature Publishing Group
The permanent address of the publication
https://urn.fi/URN:NBN:fi:jyu-202208294388Use this for linking
Review status
Peer reviewed
ISSN
2041-1723
DOI
https://doi.org/10.1038/s41467-022-32669-3
Language
English
Published in
Nature Communications
Citation
- Huang, Y.-T., Kavanagh, S. R., Righetto, M., Rusu, M., Levine, I., Unold, T., Zelewski, S. J., Sneyd, A. J., Zhang, K., Dai, L., Britton, A. J., Ye, J., Julin, J., Napari, M., Zhang, Z., Xiao, J., Laitinen, M., Torrente-Murciano, L., Stranks, S. D., . . . Hoye, R. L. Z. (2022). Strong absorption and ultrafast localisation in NaBiS2 nanocrystals with slow charge-carrier recombination. Nature Communications, 13, Article 4960. https://doi.org/10.1038/s41467-022-32669-3
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Funder(s)
European Commission
Funding program(s)
Research infrastructures, H2020
Research infrastructures, H2020
Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Education and Culture Executive Agency (EACEA). Neither the European Union nor EACEA can be held responsible for them.
Additional information about funding
Y.-T.H. would like to thank funding from the Ministry of Education, Taiwan as well as Downing College Cambridge. S.R.K. acknowledges the Engineering and Physical Sciences Research Council (EPSRC) Centre for Doctoral Training in the Advanced Characterisation of Materials (CDT-ACM) (no. EP/S023259/1) for funding a PhD studentship, as well as the UCL Kathleen High Performance Computing Facility (Kathleen@UCL), the Imperial College Research Computing Service and associated support services. By the membership of the UK’s HEC Materials Chemistry Consortium, which is funded by EPSRC (no. EP/L000202, EP/R029431 and EP/T022213), this work used the ARCHER2 UK National Supercomputing Service and the UK Materials and Molecular Modelling (MMM) Hub (Young; EPSRC no. EP/T022213). L.M.H. and M.R. thank EPSRC for funding (no. EP/V010840/1). L.M.H. acknowledges support through a Hans Fischer Senior Fellowship from the Technical University of Munich’s Institute for Advanced Study, funded by the German Excellence Initiative. S.J.Z. acknowledges support from the Polish National Agency for Academic Exchange within the Bekker programme (grant no. PPN/BEK/2020/1/00264/U/00001). I.L. acknowledges the AiF project (ZIM-KK5085302DF0) for financial support. A.J.S would like to thank the Royal Society Te Apārangi and the Cambridge Commonwealth European and International Trust for their financial support. A.J.B. acknowledges support from the Henry Royce Institute (EPSRC grants: EP/P022464/1, EP/R00661X/1), which funded the VXSF Facilities within the Bragg Centre for Materials Research at Leeds (https://engineering.leeds.ac.uk/vxsf). The ToF-ERDA measurements and analysis were supported by the RADIATE project under the Grant Agreement 824096 from the EU Research and Innovation programme HORIZON 2020. K.Z. would like to acknowledge the EPSRC Centre for Doctoral Training in Graphene Technology (no. EP/L016087/1) for studentship. D.O.S. acknowledges support from EPSRC (no. EP/N01572X/1) and the European Research Council, ERC (no. 758345). S.D.S. acknowledges support from the Royal Society and Tata Group (no. UF150033), EPSRC (no. EP/R023980/1 and EP/S030638/1) and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (HYPERION, no. 756962). A.R. acknowledges support from EPSRC. R.L.Z.H. would like to thank the Royal Academy of Engineering through the Research Fellowship scheme (no. RF\201718\1701) and EPSRC (no. EP/V014498/1).
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