Highly air-stable CH3NH3PbI3 solar cells with the solution-processed NiOx hole transport layers

NiO is widely applied as the hole transport layer (HTL) in the high-efficient organic-inorganic hybrid perovskite solar cells (PSCs) due to its stable optical and electrical properties, especially its energy level matches well with the perovskite . We had prepared the inverted planar CH 3 NH 3 PbI 3 PSCs with the solution-processed NiO x -HTLs, and investigated the effects of NiO x precursor solution concentrations on photovoltaic performance and air-stability of PSCs. The un-encapsulated PSCs with the optimized NiO x -0.125 HTLs exhibit a large open-circuit voltage of 1.05 V and high power conversion efficiency of 16.69%. After being exposed to the atmospheric air for 720 hours, it still keeps ∼95% of the initial open-circuit voltage and ∼75% of the initial power conversion efficiency, showing better air-stability than previous CH 3 NH 3 PbI 3 cells with the solution-processed NiO x -HTLs.