Optimisation of PCPDTBT solar cells using polymer synthesis with Suzuki coupling

Process optimisation for the fabrication of PCPDTBT/PCBM-based bulk heterojunction solar cells using polymers synthesised by Suzuki coupling is described. The relationship between the chemical purity of the polymers and the performance of the devices was examined and by using a combination of OFET, OPV and hole-only devices, the best polymer purification technique identified. The purified polymers were used to optimise the fabrication of solar cells by varying the donor–acceptor blend ratio, the film thickness, the drying conditions and the concentration of the dithiol process additive.