Enhancing photoresponse by synergy of electric double layer gate and illumination in single CuTCNQ NW field effect transistors

Abstract

We report that photoresponse of a single metal-organic charge transfer complex Cu:TCNQ nanowire (NW) can be enhanced simultaneously by illumination as well as applying a gate bias in an Electric Double Layer Field Effect Transistor (EDL-FET) configuration fabricated on Cu:TCNQ as a channel.It is observed that applying a bias using an EDL gate to a n-channel Cu:TCNQ single NW FET, one can enhance the photoresponse of the Cu:TCNQ substantially over that which arise from the photoconductive response alone. Electron-hole pairs that generate in the NW under illuminated of wavelength 400nm gives rise photo current. Also, electric double layer induce negative charges in the NW channel which effectively increases the carrier concentration, contributing to better response in conduction. The effect reported here has a generic nature that gives rise to a class of gated photodetectors of different photoresponsive materials.