Computational analysis of chalcogenides as an inorganic hole transport layer in perovskite solar cells

Fill factor (FF) deficit and stability is a primary concern and challenge with the perovskite solar cell. The band alignment and resistance at the junction interface further decreases the fill factor and thus limits the performance of the device. Moreover, degradation of the intrinsic properties of the upcoming perovskite material such as methylammonium lead halide on exposure to ambience or moisture creates instability and decreases the shelf life of the device. To overcome all these challenges, we have engineered the device structure and introduces an earth-abundant material in the primitive perovskite structure by introducing an inorganic hole transport layer (HTL). It was observed from the calculation that the FF is sensitive to the band offset values. Moreover, the band alignment/band offset role and effect at the Perovskite/HTL junction were investigated. It is evident from the calculation that the inorganic material replacing Spiro-MeOTAD can enhance the stability of the device by providing insulation from ambient. The efficiency of SnS and spiro-MeOTAD were found to be comparable in the present work and thus the shelf life and moisture sensitivity challenge of the perovskite solar cell is addressed. Moreover, this work paves the way for earth-abundant p-type chalcogenides tin selenide (SnS) as a HTL layer in the perovskite solar cell.