Synthesis of π-extended low bandgap polymer based on isoindigo and thienyl-vinylene for high-performance polymer solar cells

Abstract

We have synthesized PSSA-g-PANIs which are self-doped conducting copolymer and then prepared the composites with GO. When the transmittances of PSSA-g-PANI and its composites are compared with that of PEDOT:PSS, PSSA-g-PANI and its composite with a small amount of GO (2.5 wt%, 5 wt%) show higher transmittance than PEDOT:PSS in the range of 450 nm to 600 nm, corresponding to the absorption range of P3HT. The electrical conductivities of PSSA-g-PANI and its composite are much larger than that of PEDOT:PSS. The device with the pristine PSSA-g-PANI shows higher PCE than that with PEDOT:PSS mainly due to enhancement of JSC. When the composite with 2.5 wt% GO was used, the device exhibits the maximum PCE of 4.14%, which is 15% larger than the device with PEDOT:PSS.