Advancing Monolithic Perovskite/TOPCon Tandem Solar Cells by Customizing Industrial‐Level Micro‐Nano Structures

Abstract Texturing silicon solar cells with micro/nano‐structures is crucial for achieving outstanding optical performance in perovskite/silicon tandem solar cells (TSCs). However, ensuring excellent electrical properties remains a challenge due to reduced passivation quality of the bottom silicon sub‐cells and difficulties in perovskite formation on textured substrates. Here, an industrial‐level sub‐micron random pyramid (sMRP) structure on the front side of a tunnel oxide passivating contact (TOPCon) solar cell using a simple alkaline texturing process is presented, resulting in excellent optical and electrical properties. Through meticulous fabrication process tuning, uniform sMRP textures with a size of 0.6–0.8 µm are achieved, exhibiting low reflectance comparable to industrial‐level micron random pyramid (MRP) structures. Optimizing annealing temperatures of double‐sided TOPCon structures textured with front‐sided sMRP and rear‐sided MRP, yields high passivation quality, with a remarkable implied open‐circuit voltage (iV_OC) of 713 mV. Furthermore, the sMRP‐textured surface facilitates the formation of a high‐quality perovskite film with larger grain sizes and fewer internal pinholes compared to the polished counterpart. Consequently, a proof‐of‐concept p‐i‐n typed perovskite/TOPCon TSC featuring sMRP textures obtains an outstanding efficiency of 28.67%, providing a promising approach for the commercial production of high‐efficiency perovskite/TOPCon TSCs.