New Candidate for Single Junction and Silicon-based Tandem Solar Cells Reaches Landmark 10% Efficiency - 2 September 2020
The photovoltaic field is currently working hard to identify the ideal candidate for a silicon-based tandem solar cell. From a material perspective, an ideal top cell has a bandgap of ~1.6 eV, high absorption coefficient, and consists of only earth abundant and ecofriendly materials. In addition, it should also be easy to manufacture, compatible with silicon, and have a long-term stable performance.
Solar cells based on antimony sulphide/selenide have all these desired properties, however, their solar cell performance was still too low with record efficiencies around the 7% range. On 20 July 2020, a team of researchers from China and Australia have reported the first antinomy sulphide/selenide with an efficiency above 10% in the journal Nature Energy .
They achieved this landmark result by optimising the deposition and post-processing step of the absorber material resulting in a significant improvement in its morphology, grain size, and a reduction in the defect density in the film. This result illustrates the potential for this material as a candidate for future silicon-based tandem solar cells.
 R. Tang, X. Wang, W. Lian, J. Huang, Q. Wei, M. Huang, Y. Yin, C. Jiang, S. Yang, G. Xing, S. Chen, C. Zhu, X. Hao, M. A. Green, and T. Chen, “Hydrothermal deposition of antimony selenosulfide thin films enables solar cells with 10% efficiency,” Nature Energy, 5, pages587–595(2020).