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

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 mu m 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 (iVOC) 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. An industrial-level sub-micron random pyramid (sMRP) structure with low reflectance is introduced on the front side of a TOPCon solar cell. These sMRP-textures facilitate the formation of a high-quality perovskite film with larger grain sizes and fewer internal pinholes. A proof-of-concept perovskite/TOPCon tandem solar cell (TSC) featuring sMRP textures exhibits a high efficiency of 28.67%, providing a promising approach for commercial TSCs. image