Laser Patterned Flexible 4T Perovskite-Cu(In,Ga)Se2 Tandem Mini-module with Over 18% Efficiency

Abstract

Perovskite-Cu(In,Ga)Se2 (CIGS) thin-film tandem technology provides an exciting prospect to achieve low-cost high-efficiency photovoltaic devices by high throughput roll-to-roll processing on flexible substrates. However, no report on flexible perovskite-CIGS mini-modules has been published due to scribing-related challenges in realizing near-infrared (NIR)-transparent perovskite mini-modules on flexible substrates. Herein, an NIR-transparent flexible perovskite mini-module with an efficiency of 10.8% and an NIR-transparency of over 75% is reported. All-laser scribed interconnection approach is used to realize monolithic interconnection of mini-modules on thermally sensitive soft flexible substrate. An analytical method is utilized to optimize the mini-module layout and achieve a geometric fill factor of over 93%. Further, as a proof of concept, a flexible perovskite-CIGS tandem mini-module with an efficiency of 18.4% on an aperture area of 2.03 cm2 is demonstrated. To conclude, pathways for improving the efficiency of flexible NIR-transparent perovskite mini-modules are discussed.