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

Abstract

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 CH3NH3PbI3 PSCs with the solution-processed NiOx-HTLs, and investigated the effects of NiOx precursor solution concentrations on photovoltaic performance and air-stability of PSCs. The un-encapsulated PSCs with the optimized NiOx-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 CH3NH3PbI3 cells with the solution-processed NiOx-HTLs.