https://doi.org/10.1051/epjap/2021210215
Regular Article
Micro-concentrated photovoltaics based on Cu(In,Ga)Se2 microcells: an optical study★
School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, 430070 Wuhan, P.R. China
* e-mail: guanchao.yin@whut.edu.cn
Received:
4
October
2021
Received in final form:
12
November
2021
Accepted:
7
December
2021
Published online: 13 January 2022
Micro-concentrated Cu(In,Ga)Se2 (µCPV-CIGSe) solar cells offer the potential to greatly reduce the consumption of raw materials while maintaining high efficiencies. A theoretical model of µCPV-CIGSe solar cells, consisting of hexagonally spaced micro-CIGSe (µ-CIGSe) solar cells embedded in the low-index dielectric matrix and µ-lenses placed on top, is proposed for optical study. It is discovered that µ-lenses enable to effectively concentrate the incident light due to the inherent nanojet phenomenon, and the µ-CIGSe absorbers trap the penetrated light within absorbers arising from wave-guided modes. The two effects co-contribute to an optimized absorption for µCPV-CIGSe solar cells with a µ-CIGSe absorber diameter of 800 nm and a pitch of 1500 nm. Short-circuit current density reaches 36.5 mA/cm2 and accounts for 98.8% compared to their plain counterparts without lenses, corresponding to an absorber material saving by a factor of 3/4. Notably, a large contacting area between lenses and CIGSe solar cells are recommended for an improved angular tolerance. Those findings will recommend design principles for further experiments.
Supplementary material is available in electronic form at https://www.epjap.org/10.1051/epjap/2021210215
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