Influence of diameter on the photoresponse in a networked zinc-oxide nanowire photodetector

We report on the photoresponses of networked ZnO nanowire photodetectors fabricated by using a simple, mass-scalable process. ZnO nanowires were synthesized by using a carbothermal reduction process and the diameter of the nanowires was controlled by using the thickness of the gold catalyst. The photoresponse was measured by using photodectors fabricated with nanowires of 80 nm and 300 nm in diameter. The photoresponse showed no dependence on the diameter of the nanowires in the wavelength range of 200 ∼ 370 nm, which is attributed to the effects of photo-generation and photolysis on the surface nanowires, while it showed a dependence on the diameter in the wavelength range of 370 ∼ 650 nm.