LAUSR

Abstract Cu(In, Ga)Se2 (CIGS) solar cells have reached efficiencies over 23%. However, the scarcity of In and Se makes reducing the thickness of CIGS thin-film absorber desirable for mass production with low-cost and time-saving processes. Meanwhile, CIGS solar cells based on different architectures and strategies have drawn much attention for significant performance over conventional technologies, but rational design guidelines for optical and electrical performance optimization are yet to be completed. In this work, the reduced thickness of the CIGS thin film with the optical and electrical loss-passivated molybdenum Voronoi nanocavity arrays (VNCAs) electrodes were demonstrated. A structural-model under conformally coating criteria was investigated and optimized by a finite-difference time-domain method. The reduced parasitic absorption and rear surface recombination by Al2O3 passivation layers on VNCAs substrates give rise to enhanced VOC and JSC up to 9.5 and 8.5%, respectively. These results confirm that the novel VNCAs electrodes can provide a cost-effective way for ultrathin CIGS solar cells with high efficiency.