Electron-Beam-Evaporated NiOX for Efficient and Stable Semi-Transparent Perovskite Solar Cells and Modules

Semi-transparent perovskite solar cells (ST-PSCs) have tremendous potential as smart windows owing to their higher efficiency and visible transmittance. However, most of previous ST-PSCs were fabricated by spin-coating methods with vulnerable materials, which are not stable at higher temperature (> 60 °C) and the processes are not scalable. Herein, thermal stable ST-PSCs have been fabricated by using vacuum deposited CsPbBr3 perovskite and electron-beam evaporation deposited NiOX. Furthermore, we further introduced an ultrathin P3HT buffer layer before depositing NiOX to avoid the damage of perovskite morphology by electron-beam. We found that this P3HT buffer layer not only protects the perovskite film from the damage of electron beam, but also facilitates the hole transfer from perovskite to NiOX. As a result, we achieved champion efficiencies of 7.1% for small area (active area = 0.16 cm2) solar cells and 5.5% for 5 cm × 5 cm mini-modules (active area = 10.0 cm2) with an AVT of 49.1%. Moreover, the non-encapsulated devices retained 93% of their initial performance after aging at 65 °C and a relative humidity (RH) of 55 ± 10% for 30 days.