Oxide/Halide/Oxide Architecture for High Performance Semi‐Transparent Perovskite Solar Cells

Abstract A device architecture with n‐type oxide/perovskite halide/p‐type oxide for the sputtering damage‐free semi‐transparent perovskite solar cells (PSCs) is reported. A p‐type nickel oxide (NiO_x) nanoparticle overlayer on a perovskite layer is introduced to act as both a hole transporting layer and buffer layer to avoid sputtering damage during deposition of transparent conducting oxide. The NiO_x based semi‐transparent PSCs exhibit superior durability under harsh sputtering conditions such as high temperature and sputtering power, enabling the high quality of transparent electrodes. With optimal sputtering condition for tin‐doped indium oxide (ITO) as a top transparent electrode, the semi‐transparent device shows an enhanced power conversion efficiency (PCE) of 19.5% (20.5% with a back reflector), which is higher than that of the opaque device (19.2%). The semi‐transparent devices also shows superior storage stability without encapsulation under 10% relative humidity, retaining over 90% of initial PCE for 1000 h. By controlling the molar concentration of perovskite solution, a semi‐transparent PSC with a PCE of 12.8%, showing a high average visible transmittance (AVT) of 30.3%, is fabricated. The authors believe that this architecture with n‐type oxide/perovskite halide/p‐type oxide represents a cornerstone for the high performance and commercialization of semi‐transparent PSCs.