Revolutionizing light capture: a comprehensive review of back-contact perovskite solar cell architectures

Abstract

Back-contact architectures are emerging as a transformative solution to overcome optical and structural limitations inherent to conventional sandwich-type perovskite solar cells (PSCs). While single-junction PSCs have reached certified power conversion efficiencies (PCEs) of up to 27.0 %, their reliance on transparent conductive oxides (TCOs) and front-contact layers introduces significant photon losses and design constraints. Interdigitated back-contact (IBC) and quasi-interdigitated back-contact (QIBC) geometries eliminate the need for front-side electrodes, enabling full-area top illumination, enhanced optical efficiency, improved mechanical flexibility, and simplified recycling. In this Review, we systematically examine the development of back-contact PSCs, focusing on the interplay between device architecture, charge carrier dynamics, and fabrication strategies. We compare state-of-the-art patterning methods, including nanoimprint lithography, microsphere templating, and electrodeposition, and summarize material systems employed for electron/hole transport and insulation. Recent experimental devices have achieved over 12 % PCE, and simulations predict efficiencies exceeding 29 %, highlighting the untapped potential of back-contact designs. We also discuss the critical challenges, such as short diffusion lengths, interfacial recombination, and fabrication scalability, and propose design guidelines to accelerate the path toward high-efficiency, manufacturable back-contact PSC technologies.