Bilayer SnO<sub>2</sub>/ZnO Buffer Layers to Achieve 21.7% Efficient CdSeTe/CdTe Solar Cells
The use of SnO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> buffer layers has led to highly efficient and stable thin film CdSeTe/CdTe solar cells. However, chlorine segregation was observed at the SnO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> /CdSeTe interface, suggesting that the quality of the p-n junction could be improved. In this work, ZnO was incorporated between the SnO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and CdSeTe to study its passivation effect. Including a ~10 nm thick ZnO layer improved conversion efficiency, V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oc</inf>, J<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sc</inf>, and FF, suggesting an improvement in junction quality. The bilayer SnO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> (70 nm)/ZnO (30 nm) buffer layer achieved an efficiency of 21.7% without an anti-reflection coating. High-resolution TEM analysis showed atomically coherent boundaries at the SnO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>/ZnO and ZnO/CdSeTe interfaces, indicating that ZnO creates a high-quality interface. The discovery that ZnO can be used as a passivation layer opens up new pathways to achieve highly efficient solar cells.
Authors
- D.A. Lamb (ORCID: https://orcid.org/0000-0002-4762-4641)
- Timothy Nagle
- John M. Walls (ORCID: https://orcid.org/0000-0003-4868-2621)
- Stuart Robertson (ORCID: https://orcid.org/0000-0001-5591-369X)
- Zhaoxia Zhou (ORCID: https://orcid.org/0000-0002-7420-0510)
- Mustafa Togay (ORCID: https://orcid.org/0000-0001-5840-2158)
- Luis C. Infante‐Ortega (ORCID: https://orcid.org/0009-0002-0640-1705)
- Luksa Kujovic (ORCID: https://orcid.org/0009-0009-3980-1933)
- Jake W. Bowers (ORCID: https://orcid.org/0000-0001-7632-1140)
- S.J.C. Irvine (ORCID: https://orcid.org/0000-0002-1652-4496)
- Gang Xiong (ORCID: https://orcid.org/0000-0002-4303-5559)
- Xiaolei Liu (ORCID: https://orcid.org/0009-0009-8788-3208)
- Wei Zhang (ORCID: https://orcid.org/0000-0001-5375-5886)
- Chungho Lee
- Dingyuan Lu (ORCID: https://orcid.org/0009-0008-4046-974X)
- Ciaran Llewelyn (ORCID: https://orcid.org/0009-0005-4074-5204)
Institutions
- Loughborough University (GB)
- Swansea University (GB)
- First Solar (United States) (US)
Publication Details
- Published
- 2025-06-08
- DOI
- https://doi.org/10.1109/pvsc59419.2025.11133075
- Primary Topic
- Chalcogenide Semiconductor Thin Films
- Type
- article
- Field-Weighted Citation Impact
- 0.00