Single CuTCNQ charge transfer complex nanowire as ultra high responsivity photo-detector.

We report ultra large photo responsivity ℜ (ratio of photo-generated current to absorbed power) in a single nanowire (NW) device made from a single strand of a nanowire (diameter ~30nm and length ~200nm) of an organomettalic semiconducting charge transfer complex material of CuTCNQ. The device shows responsivity of 8x10(4) A/Watt at 1 volt applied bias with an enhancement over the dark current exceeding 10(5) at zero bias. The observed photo current has a spectral dependence that strongly follows the main absorption peak (close to 405 nm) showing the primary role of absorbed photo-generated carriers.