This final report outlines the project’s development of antimony chalcogenide thin film PV materials and the production of antimony chalcogenide/Si tandem solar cell to develop a novel cost effective and higher efficiency solar cells. This report discusses key highlights and lessons learnt throughout the project.
Report extract
The project aims to improve the cost effectiveness of current mass-market Silicon (Si) solar panels by developing high efficiency Si-based tandem cells with our proposed antimony chalcogenide (Sb2(S,Se)3) thin film photovoltaic (PV) material. To achieve lower levelized cost of energy (LCOE) of Si tandem cells than Si cells, while with improved efficiency, the requirement for low degradation rate of Si tandemsis also critical. According to International Technology Roadmap for Photovoltaic (ITRPV), a Si-based tandem cell needs to follow the criteria of <2% degradation after the first year of operation and 0.5% per year afterwards. Despite the reported progress on the high bandgap top cells, there is no affirmable top cell solution yet to meet the above requirements of stability, cost-effectiveness and high-efficiency due to either the poor stability, toxicity (perovskite solar cells), and/or scarce constituent (high bandgap Copper Indium Gallium Sulfide, CIGS, solar cells), and/or relatively low performance (high bandgap kesterite solar cells), compromising the possible availability of a fully sustainable thin film PV technology for Si-based tandem cells in a reasonable time-frame. Our project focuses on an alternative top cell which is ultra-thin, uses abundant and Restriction of Hazardous Substances (RoHS)-compliant materials and has long-term stable performance. Besides, it can be manufactured using a highly compatible and cost-effective process thus providing an appealing option for Si-based tandem solar cells.