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Cation disorder engineering yields AgBiS2 nanocrystals with enhanced optical absorption for efficient ultrathin solar cells

Nature Photonics volume 16, pages 235–241 (2022)Cite this article

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An Author Correction to this article was published on 25 March 2022

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Abstract

Strong optical absorption by a semiconductor is a highly desirable property for many optoelectronic and photovoltaic applications. The optimal thickness of a semiconductor absorber is primarily determined by its absorption coefficient. To date, this parameter has been considered as a fundamental material property, and efforts to realize thinner photovoltaics have relied on light-trapping structures that add complexity and cost. Here we demonstrate that engineering cation disorder in a ternary chalcogenide semiconductor leads to considerable absorption increase due to enhancement of the optical transition matrix elements. We show that cation-disorder-engineered AgBiS2 colloidal nanocrystals offer an absorption coefficient that is higher than other photovoltaic materials, enabling highly efficient extremely thin absorber photovoltaic devices. We report solution-processed, environmentally friendly, 30-nm-thick solar cells with short-circuit current density of 27 mA cm−2, a power conversion efficiency of 9.17% (8.85% certified) and high stability under ambient conditions.

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Fig. 1: Absorption enhancement via cation disorder homogenization.
Fig. 2: Absorption coefficients and optical modelling.
Fig. 3: Characterization of cation configuration transition.
Fig. 4: Ultrathin AgBiS2 NC solar cells.

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Data availability

The experimental and computational data that support the current study are available in a public repository (https://doi.org/10.5281/zenodo.5733213). Supplementary Information data are available from the corresponding author upon reasonable request.

Code availability

The code that supports this study is available in a public repository (https://doi.org/10.5281/zenodo.5733213).

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Acknowledgements

G.K. acknowledges financial support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 725165), the Fundació Joan Ribas Araquistain (FJRA), the Fundació Privada Cellex, the program CERCA, EQC2019-005797-P (AEI/FEDER UE), 2017SGR1373 and ‘Severo Ochoa’ Centre of Excellence CEX2019-000910-S funded by the Spanish State Research Agency. Y.W. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 754558. I.B.-C. acknowledges support from the Government of Catalonia’s Beatriu de Pinós postdoctoral programme (grant no. 2017BP00241). S.R.K. thanks L. Harnett-Caulfield for help with using the alloy theoretic automated toolkit software package and Y.-S. Choi for help with calculating the Madelung potentials; he also acknowledges the EPSRC Centre for Doctoral Training in the Advanced Characterisation of Materials (CDT-ACM) (EP/S023259/1) for funding a PhD studentship. A.W. and D.O.S. acknowledge the use of 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 the EPSRC (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 (Thomas EP/P020194 and Young EP/T022213). D.O.S. acknowledges support from the EPSRC (EP/N01572X/1) and the European Research Council, ERC (grant no. 758345).

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Author notes

  1. These authors contributed equally: Yongjie Wang, Seán R. Kavanagh.

Authors and Affiliations

  1. ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain

    Yongjie Wang, Ignasi Burgués-Ceballos & Gerasimos Konstantatos

  2. Thomas Young Centre and Department of Chemistry, University College London, London, UK

    Seán R. Kavanagh & David O. Scanlon

  3. Thomas Young Centre and Department of Materials, Imperial College London, London, UK

    Seán R. Kavanagh & Aron Walsh

  4. Department of Materials Science and Engineering, Yonsei University, Seoul, Republic of Korea

    Aron Walsh

  5. ICREA—Institució Catalana de Recerca i Estudia Avançats, Barcelona, Spain

    Gerasimos Konstantatos

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Contributions

G.K. supervised and directed the study. Y.W. and G.K. conceived the idea, designed this study and co-wrote the manuscript, with feedback from the co-authors. Y.W. synthesized the AgBiS2 NCs, performed the material characterization, fabricated and characterized the solar cells, and analysed the data, with help from I.B.-C. Y.W. performed the optical modelling. S.R.K. designed and conducted the theoretical modelling, analysed the DFT simulations, interpreted the data, provided insights and contributed to manuscript writing. D.S and A.W. supervised the theoretical modelling.

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Correspondence to Gerasimos Konstantatos.

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Wang, Y., Kavanagh, S.R., Burgués-Ceballos, I. et al. Cation disorder engineering yields AgBiS2 nanocrystals with enhanced optical absorption for efficient ultrathin solar cells. Nat. Photon. 16, 235–241 (2022). https://doi.org/10.1038/s41566-021-00950-4

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