Anomalous increase of photocurrent anisotropy in a liquid crystalline binary mixture

We report photoconductivity measurements in a binary system of naphthalene-based liquid crystals. Under ultraviolet (365 nm) illumination we observe an anomalous increase in the photocurrent for the mixtures. For a particular concentration, the photocurrent anisotropy defined as the ratio of photocurrents orthogonal to and along the director in the Crystal E phase reaches a value of 850, the highest achieved under steady-state illumination conditions from a conventional source. We argue that when using such mixtures, it is possible to reach the limiting values predicted by models based on conduction dictated by charge-carrier hopping.