Hot‐Pressing Transfer of Diffraction‐Grating Perovskite for Efficient Bifacial Perovskite Solar Cells

Abstract Compared with monofacial solar cells, the development of bifacial solar cells has garnered considerable attention for achieving higher power output by simultaneously harvesting direct and diffused light while incurring fewer additional manufacturing costs. Perovskite light absorbers, given their outstanding optoelectronic properties, present great opportunities for fabricating bifacial solar cells. However, one of the challenges in designing bifacial perovskite solar cells (PSCs) is that they suffer from optical and electrical losses due to insufficient light absorption in the perovskite layer. In this respect, in this work, a hot‐pressing transfer process is developed to fabricate a diffraction‐grating (DG) perovskite layer to form a bifacial PSC. The constructed DG structure on the perovskite layer improved its light‐harvesting efficiency, reduced its charge recombination, and enhanced its charge extraction properties. The bifacial DG PSC achieved power conversion efficiencies of 14.01% and 10.04% for the bottom and top illuminations, respectively, resulting in a bifaciality factor of 0.71. Therefore, the newly developed hot‐pressing transfer process for fabricating DG structures on perovskite layers is a promising technique for fabricating high‐efficiency bifacial PSCs with high bifaciality factors.