W 18O 49 nanowires as ultraviolet photodetector

Abstract

Photodetectors in a configuration of field effect transistor were fabricated based on individual W 18O 49 nanowires. Evaluation of electrical transport behavior indicates that the W 18O 49 nanowires are n-type semiconductors. The photodetectors show high sensitivity, stability and reversibility to ultraviolet (UV) light. A high photoconductive gain of 10 4 was obtained, and the photoconductivity is up to 60 nS upon exposure to 312 nm UV light with an intensity of 1.6 mW/cm 2. Absorption of oxygen on the surface of W 18O 49 nanowires has a significant influence on the dark conductivity, and the ambient gas can remarkably change the conductivity of W 18O 49 nanowire. The results imply that W 18O 49 nanowires will be promising candidates for fabricating UV photodetectors. © 2009 The Author(s).