Sustainable Manufacturing of Perovskite-CIGS Tandem Solar Cells through Lamination with Metal-Free Transparent Conductive Adhesives

Perovskite-CIGS tandem solar cells offer unique benefits, such as high efficiencies and the possibility for cost-effective production on flexible, lightweight substrates. Yet, scaling up the production of these devices presents challenges, particularly because of roughness, solvents, and reactions that can impair the integrity of subcells within tandem configurations. Here, we introduce a metal-free transparent conductive adhesive (TCA) material, implemented via a lamination approach, as a scalable solution that facilitates separate fabrication and subsequent tandem integration of the subcells. This TCA not only exhibits promising electrical and optical properties but also ensures that its lamination process does not degrade the perovskite. It also exhibits encapsulation properties rivaling those of commercial encapsulants. By employing this TCA, we have attained a champion efficiency of 20.6% in single-junction semitransparent solar cells, featuring a high fill-factor of 79.7%. Ultimately, we demonstrate its compatibility with perovskite-CIGS tandem solar cells, effectively eliminating the need for additional encapsulation while opening pathways for the separate recycling of perovskite-based tandems.