Enhancement In Open-Circuit Voltage Of Semi-Transparent Mapbi(3-X)Br(X) Perovskite Solar Cells By Methyl Amine Treatment And Optimal Hole Transport Layer

Wide bandgap perovskites (>1.7 eV) find applications in multi-junction solar cells and semi-transparent absorbers for building integrated photo-voltaics. Here we present the improvement in morphology and power conversion efficiency (PCE) of two mixed halide perovskite compositions: MAPbIBr(2) and MAPbBr(3) by methyl amine (MA) vapor treatment. MA treatment improves the morphology and surface coverage leading to increase in open-circuit voltage (V-oc) and short-circuit current (J(sc)). Further two polymers are used as hole-transporting materials which have better HOMO matching with perovskite than Spiro-OMeTAD and results in V-oc of 1.12 V and 1.17 V for MAPbIBr(2) and MAPbBr(3) respectively compared to 0.95 V and 1.10 V of the corresponding devices with Spiro-OMeTAD as HTL.