Improved device performances of organic solar cells with Au cathode using a phosphine sulfide type cathode modification layer

Organic solar cells (OSCs) with Au as an electron collecting electrode were developed using a phosphine sulfide type cathode modification layer. Spirobifluorene based phosphine sulfide was used as the interlayer between the poly(3-hexylthiophene): 6,6-phenyl C61-butyric acid methyl ester active layer and Au electrode. The open circuit voltage of the OSC was enhanced from 0.31 to 0.56 V and the efficiency was improved from 1.04 to 2.73% by the phosphine sulfide type cathode modification layer.