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

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.