Enhanced performance of planar perovskite solar cells via incorporation of Bphen/Cs2CO3 MoO3 double interlayers
Abstract This work proposes a new perovskite solar cell structure by inserting the double modified interlayers consisting of the 4,7 diphenyl 1,10 phenanthroline (Bphen) and cesium carbonate (Cs2CO3) MoO3 layer between perovskite (CH3NH3PbI3 xClx)/PCBM (phenyl C61 butyric acid methylester) and an Ag electrode. The double interlayers improve the photovoltaic efficiency to 15.59% which is higher than that of reference devices with Bphen (13.41% or alone, the champion PCE of 16.01% is obtained. The enhanced opening circuit voltage (Voc) is ascribed as the main factor to improve the efficiency. Further studies show, the reduced work function of cathode by means of the Cs2CO3 MoO3 could effectively extract the electrons and reduce the carrier recombination and thus result in a higher Voc.