Recent studies have shown that charge transport interlayers with low gas permeability can increase the operational lifetime of perovskite solar cells serving as a barrier for migration of volatile decomposition products from the photoactive layer. Herein we present a hybrid hole transport layer (HTL) comprised of p-type polytriarylamine (PTAA) polymer and vanadium(V) oxide (VO x ). Devices with PTAA/VO x top HTL reach up to 20% efficiency and demonstrate negligible degradation after 4500 h of light soaking, whereas reference cells using PTAA/MoO x as HTL lose ∼50% of their initial efficiency under the same aging conditions. It was shown that the main origin of the enhanced device stability lies in the higher tolerance of VO x toward MAPbI 3 compared to the MoO x interlayer, which tends to facilitate perovskite decomposition. Our results demonstrate that the application of PTAA/VO x hybrid HTL enables long-term operational stability of perovskite solar cells, thus bringing them closer to commercial applications.

We report gas sensors based on formamidinium lead chloride (FAPbCl3), which demonstrate a strong and outstandingly selective response towards ammonia due to the specific interaction of the halide vacancies with NH3.