Revolutionizing photovoltaics: From back-contact silicon to back-contact perovskite solar cells

Interdigitated back-contact (IBC) electrode configuration is a novel approach toward highly efficient Photovoltaic (PV) cells. Unlike conventional planar or sandwiched configurations, the IBC architecture positions the cathode and anode contact electrodes on the rear side of the solar cell. This review provides a comprehensive overview of back-contact (BC) solar cells, commencing with the historical context of the inception of the back-contact silicon (BC-Si) solar cells and its progression into various designs such as metallization wrap through, emitter wrap through, and interdigitated configurations. This review emphasizes back-contact perovskite solar cells (BC-PSCs), due to their potential for achieving higher efficiencies and better stability compared to traditional PSC architectures. Herein, we discuss the classification of BC-PSCs based on the position of rear electrodes, including interdigitated and quasi-interdigitated structures. These structures are further analyzed by investigating their implementation via various electrode patterning techniques, such as photolithography, microsphere lithography, cracked film lithography, network-like porous titanium (Ti) electrodes, v-shaped grooves, and lateral-structure perovskite single crystal/shadow masks, used in the development of various types of BC-PSCs. Finally, this review concludes by suggesting potential solutions to the current challenges associated with BC-PSCs to tap into the full potential of this technology. This review aims to provide readers with an in-depth understanding of the latest advancements in BC PV technology, particularly BC-PSCs, and the potential directions for future research and innovation.