1. Incorporation of CdSe layers into CdTe thin film solar cells
- Author
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Leon Bowen, Silvia Mariotti, Ken Durose, Tom Baines, Jonathan D. Major, Thomas P. Shalvey, and Guillaume Zoppi
- Subjects
Materials science ,Annealing (metallurgy) ,Band gap ,H600 ,J100 ,Oxide ,02 engineering and technology ,7. Clean energy ,01 natural sciences ,chemistry.chemical_compound ,0103 physical sciences ,010302 applied physics ,Bandgap grading ,Renewable Energy, Sustainability and the Environment ,business.industry ,Open-circuit voltage ,Carrier lifetime ,021001 nanoscience & nanotechnology ,Cadmium telluride photovoltaics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Optoelectronics ,Thin film solar cell ,0210 nano-technology ,business - Abstract
Incorporation of CdSe layers into CdTe thin film solar cells has recently emerged as a route to improve cell performance. It has been suggested that the formation of lower band gap CdTe(1-x)Se(x) phases following Se diffusion induces bandgap grading which may increase the carrier lifetime and thereby open circuit voltage. In this study we investigate the impact of CdSe incorporation on CdTe solar cell performance. We demonstrate that the standard CdS/CdTe device architecture is incompatible with Se incorporation, owing to large optical losses. An alternative cell structure with an oxide partner layer replacing the CdS with SnO2/CdSe/CdTe is developed, leading to cell efficiencies of > 13.5%. The differences in processing required for effective selenium incorporation are investigated with performance improvements resulting from additional post-growth annealing. Finally, other oxides such as TiO2, ZnO and FTO are demonstrated to be unsuitable partner layers but highlight that the choice of partner layer is key to further improving the performance.
- Published
- 2018
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