Air-stable perovskite photovoltaic cells with low temperature deposited NiOx as an efficient hole-transporting material

The electron-beam physical vapor deposition (EBPVD) technique was selected for nickel oxide (NiO x ) film deposition at room temperatures. NiO x film (18 nm thick) was deposited as a hole transporting material (HTM) for inverted perovskite solar cells (PSCs) onto a fluorine-doped tin oxide (FTO)-coated glass substrate at a chamber vacuum pressure of 4.6×10 4 Pa. PSCs were fabricated as a glass/FTO/NiO x (HTM)/CH 3 NH 3 PbI 3 /PC 61 BM/BCP/Ag structure with as-deposited and annealed (500 °C for 30 min) NiOx films. Under 100 mW cm -2 illumination, as-deposited and annealed NiO x as HTM in PSCs (0.16 cm 2 ) showed a high-power conversion efficiency (PCE) of 13.20% and 13.24%, respectively. The as-deposited and annealed PSCs retained 72.2% and 76.96% of their initial efficiency in ambient conditions, correspondingly. This study highlights the possibility of achieving highly crystalline and finely disseminated NiO x films by EBPVD for fabricating efficient inverted PSCs.