Unveiling the Role of Guanidinium for Enhanced Charge Extraction in Inverted Perovskite Solar Cells
The incorporation of guanidinium (Gua) cations has significantly enhanced the optoelectronic properties of various perovskite compositions. When combined with other A-site cations in perovskite solar cells (PSCs), Gua cations not only enhance the power conversion efficiency of the solar cells but often improve their overall stability. While most studies examining the impact of Gua focus on PSCs with the n-i-p (conventional) structure, fewer have investigated its effects on the mechanism and performance of the p-i-n (inverted) structure. We investigate how partially substituting A-site cations with Gua affects the performance of PSCs and the associated charge carrier dynamics. Enhanced performance is observed in Gua-substituted inverted PSCs, primarily due to improved short-circuit current density and fill factor values. Our spectroscopic and microscopic analyses reveal that these enhancements stem from accelerated charge transport within the perovskite layer combined with inhibited ion migration following Gua incorporation, attributed to the reduction of localized inhomogeneities, which also notably enhance device stability. Our findings elucidate the role of Gua in inverted PSCs, showing negligible impact on open-circuit voltage but significant improvement in charge extraction efficiency. This contrasts with previous reports on conventional structures, where performance enhancement is primarily attributed to trap state reduction, resulting in higher open-circuit voltage.
Authors
- Weidong Xu (ORCID: https://orcid.org/0000-0002-3934-8579)
- Caterina Ducati (ORCID: https://orcid.org/0000-0003-3366-6442)
- Martyn A. McLachlan (ORCID: https://orcid.org/0000-0003-3136-1661)
- Yueyao Dong (ORCID: https://orcid.org/0000-0003-4571-3146)
- Elizabeth von Hauff (ORCID: https://orcid.org/0000-0002-6269-0540)
- Chieh‐Ting Lin (ORCID: https://orcid.org/0000-0002-9591-0888)
- Thomas Webb (ORCID: https://orcid.org/0000-0002-6921-693X)
- Giorgio Divitini (ORCID: https://orcid.org/0000-0003-2775-610X)
- Richard A. Pacalaj (ORCID: https://orcid.org/0000-0002-6242-3880)
- Ziyuan Ge (ORCID: https://orcid.org/0000-0001-7820-2073)
- Artem A. Bakulin (ORCID: https://orcid.org/0000-0002-3998-2000)
- Guanjie He (ORCID: https://orcid.org/0000-0002-7365-9645)
- Felix Utama Kosasih (ORCID: https://orcid.org/0000-0003-1060-4003)
- Thomas J. Macdonald (ORCID: https://orcid.org/0000-0002-7520-6893)
- Marcello Righetto (ORCID: https://orcid.org/0000-0001-5507-1445)
- Ganghong Min (ORCID: https://orcid.org/0000-0001-8322-7304)
- Saif A. Haque (ORCID: https://orcid.org/0000-0001-5483-3321)
- Samuel D. Stranks (ORCID: https://orcid.org/0000-0002-8303-7292)
- Franco Cacialli (ORCID: https://orcid.org/0000-0001-6821-6578)
- James Robert Durrant (ORCID: https://orcid.org/0000-0001-8353-7345)
- Tong Wang (ORCID: https://orcid.org/0000-0001-9032-1569)
- Tian Du (ORCID: https://orcid.org/0000-0002-0566-1145)
- Muzi Chen (ORCID: https://orcid.org/0009-0009-4262-1095)
- Qichun Gu (ORCID: https://orcid.org/0009-0004-1399-7601)
- Mischa Hillenius
Institutions
- National Chung Hsing University (TW)
- Free University of Bozen-Bolzano (IT)
- Forschungszentrum Jülich (DE)
- University of Cambridge (GB)
- Clarendon College (US)
- London Centre for Nanotechnology (GB)
- Italian Institute of Technology (IT)
- University of Oxford (GB)
- Max-Planck-Institut für Kohlenforschung (DE)
- Helmholtz Institute Erlangen-Nürnberg (DE)
- Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology (DE)
- University College London (GB)
- Imperial College London (GB)
- Technische Universität Dresden (DE)
- Vrije Universiteit Amsterdam (NL)
Publication Details
- Journal
- ACS Energy Letters
- Published
- 2025-05-09
- DOI
- https://doi.org/10.1021/acsenergylett.5c00469
- Citations
- 5
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 3.65
Funders
- Leverhulme Trust
- Royal Society
- Royal Commission for the Exhibition of 1851
- Cambridge Trust
- Tata Sons
- Engineering and Physical Sciences Research Council
- H2020 European Research Council