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Williams RE, Ramasse QM, McKenna KP, Phillips LJ, Yates PJ, Hutter OS, Durose K, Major JD, Mendis BG. Evidence for Self-healing Benign Grain Boundaries and a Highly Defective Sb 2Se 3-CdS Interfacial Layer in Sb 2Se 3 Thin-Film Photovoltaics. ACS Appl Mater Interfaces 2020; 12:21730-21738. [PMID: 32314567 DOI: 10.1021/acsami.0c03690] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The crystal structure of Sb2Se3 gives rise to unique properties that cannot otherwise be achieved with conventional thin-film photovoltaic materials, such as CdTe or Cu(In,Ga)Se2. It has previously been proposed that grain boundaries can be made benign provided only the weak van der Waals forces between the (Sb4Se6)n ribbons are disrupted. Here, it is shown that non-radiative recombination is suppressed even for grain boundaries cutting across the (Sb4Se6)n ribbons. This is due to a remarkable self-healing process, whereby atoms at the grain boundary can relax to remove any electronic defect states within the band gap. Grain boundaries can, however, impede charge transport due to the fact that carriers have a higher mobility along the (Sb4Se6)n ribbons. Because of the ribbon misorientation, certain grain boundaries can effectively block charge collection. Furthermore, it is shown that CdS is not a suitable emitter to partner Sb2Se3 due to Sb and Se interdiffusion. As a result, a highly defective Sb2Se3 interfacial layer is formed that potentially reduces device efficiency through interface recombination.
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Affiliation(s)
- Rhys E Williams
- Department of Physics, Durham University, South Road, Durham DH1 3LE, U.K
| | - Quentin M Ramasse
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, U.K
- SuperSTEM Laboratory, Daresbury Science and Innovation Campus, Daresbury WA4 4AD, U.K
| | - Keith P McKenna
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
| | - Laurie J Phillips
- Stephenson Institute for Renewable Energy, Department of Physics, University of Liverpool, Liverpool L69 7ZF, U.K
| | - Peter J Yates
- Stephenson Institute for Renewable Energy, Department of Physics, University of Liverpool, Liverpool L69 7ZF, U.K
| | - Oliver S Hutter
- Stephenson Institute for Renewable Energy, Department of Physics, University of Liverpool, Liverpool L69 7ZF, U.K
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| | - Ken Durose
- Stephenson Institute for Renewable Energy, Department of Physics, University of Liverpool, Liverpool L69 7ZF, U.K
| | - Jonathan D Major
- Stephenson Institute for Renewable Energy, Department of Physics, University of Liverpool, Liverpool L69 7ZF, U.K
| | - Budhika G Mendis
- Department of Physics, Durham University, South Road, Durham DH1 3LE, U.K
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