Electrical properties of Ohmic contacts to ZnSe nanowires and their application to nanowire-based photodetection

Multilayer Ti/Au contacts were fabricated on individual, unintentionally doped zinc selenide nanowires with 80 nm nominal diameter. Four-terminal contact structures were used to independently measure current-voltage characteristics of contacts and nanowires. Specific contact resistivity of Ti/Au contacts is 0.024 Omega cm(2) and intrinsic resistivity of the nanowires is approximately 1 Omega cm. The authors have also measured the spectral photocurrent responsivity of a ZnSe nanowire with 2.0 V bias across Ti/Au electrodes, which exhibits a turnon for wavelengths shorter than 470 nm and reaches 22 A/W for optical excitation at 400 nm. (c) 2006 American Institute of Physics.