Charge transport in perovskite solar cells – a material interface study of transition metal chalcogenides with MAPbX3

Hetero junctions are expected to show an induced electric field generation at their material interface/s that influences the exci-ton separation and transport in solar cell devices. Since Perov-skite Solar cells (PSCs) having multi material junction interfac-es in their configurations, their performance is inevitably influ-enced by this feature. The differences in the crystallization process at the confluences of the materials regarding manufac-turing might lead to differences in the electronic charge rear-rangement between the materials and form an induced electric field generation. In this study, an Ab initio Density Functional Theory (DFT) study is employed to scrutinize the charge re-distribution among the MAPbI3 and two-dimensional (2D) lay-ered, transition metal chalcogenides (TMCs, i.e., TcS2, TcSe2) material interfaces. These 2D materials have been assessed for their potential feasibility for either electron or hole transporting layers (ETL and HTL) application in PSCs. The electronic band edges of these materials were compared between three MAPbX3 (X=Cl, Br, or I) materials to investigate this possibility for PSCs. Quantitative inter layer charge redistribution and internal electric field analysis between perovskite and these TMCs is conducted and compared using Bader charge analysis. The effects of induced strain in 2D materials, because of lattice mismatch on band edge positions, is also delineated. The re-vised band edges have considerably altered the initially predict-ed charge transport effectiveness.