Ferroelectricity and bulk photovoltaic effect of quinquethiophene derivatives bearing lactic ester moieties

Abstract

Ferroelectric liquid crystal based on a quinquethiophene core bearing lactate moieties was synthesized for an improvement of a bulk photovoltaic effect in the ferroelectric liquid crystal phase. The quinquethiophene derivative exhibited bulk photovoltaic effect in the ordered chiral smectic phase where the liquid crystal molecules tilted from the layer normal. For PCBM-doped compound 1, the open-circuit voltage was 0.72 V and the short-circuit current was 270 μAcm−2, for white light illumination (2.4 mWcm−2) resulting in the improvement of the power conversion efficiency to 0.7%.