Enhanced Light Transmittance of Electron Transport Layer through Bilayer SnO 2 for High‐Performance Semitransparent Perovskite Solar Cells

and boosts efficiency up to a certified value of 20.22 %. Furthermore, the device demonstrates an 81.4 % bifaciality and maintains 91.47 % of its initial efficiency after exposure to 1000 hours under 1-sun white LED illumination.