Simple fabrication of a ZnO nanowire photodetector with a fast photoresponse time

A zinc oxide (ZnO) nanowire photodetector was fabricated by a simple method of growing ZnO nanowires bridging the gap of two patterned zinc electrodes. The nanowire growth is self-catalytic, involving the direct heating of patterned Zn electrodes at $700°\mathrm{C}$ in an ${\mathrm{O}}_2∕\mathrm{Ar}$ gas flow of $20\mathrm{SCCM}$ (standard cubic centimeter per minute at STP)/$80\mathrm{SCCM}$ , respectively, at atmospheric pressure for $3\mathrm{h}$ . The fabricated photodetector demonstrated fast response of shorter than $0.4\mathrm{ms}$ to UV illumination in air, which could be attributed to the adsorption, desorption, and diffusion of water molecules in the air onto the nanowire significantly influencing the photoresponse.