D-π-A-π-D type benzothiadiazole-triphenylamine based small molecules containing cyano on the π-bridge for solution-processed organic solar cells with high open-circuit voltageElectronic supplementary information (ESI) available: Synthetic procedures, CV curves, calculation method and devices fabrication details. See DOI: 10.1039/c2cc35754b

Two novel D-π-A-π-D structured small molecules composed of benzothiadiazole and triphenylamine were designed and synthesized. BDCTBT with cyano on the π-bridge exhibited a deep HOMO energy level, resulting in an impressive V OC of up to 1.04 V with a PCE of 3.85%, while non-cyano substituted BDETBT yielded a V OC of 0.94 V and a PCE of 1.99%. Benzothiadiazole-triphenylamine based small molecules containing cyano on the π-bridge for solution-processed photovoltaic cells with high open-circuit voltage were designed and synthesized.