Electron-beam-evaporated NiOX for efficient and stable semi-transparent perovskite solar cells and modules

Abstract

Semi-transparent perovskite solar cells (ST-PSCs) have tremendous potential as smart windows owing to their higher efficiency and visible transmittance. However, most previous ST-PSCs were fabricated by spin-coating methods with decomposable materials, which are not stable at higher temperature (>60 °C), and the processes are not scalable. Herein, thermally stable ST-PSCs have been fabricated by using vacuum deposited CsPbBr₃ perovskite and electron-beam evaporation deposited NiO_X. Furthermore, we further introduced an ultrathin P3HT buffer layer before depositing NiO_X to avoid the damage of perovskite morphology by the electron beam. We found that this P3HT buffer layer not only protects the perovskite film from damage by the electron beam, but also facilitates the hole transfer from perovskite to NiO_X. 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.