Non-stoichiometric W(18)O(49-x)S(x) nanowires for wide spectrum photosensors with high internal gain.

This study reports successful synthesis of non-stoichiometric single-crystal W18O49-xSx nanowires for photosensors with a high absorption rate (>83%) across a wide spectrum (300-2000 nm), a high internal gain (G = 10(6)-10(7)) and a relatively fast response time (approximately 1-3 s). In addition, the correlation between the photoconductivity gain (G) and the surface-to-volume ratio of non-stoichiometric single-crystal W18O49-xSx nanowires was studied. The surface-to-volume ratio and non-stoichiometric material of W18O49-xSx contributed to the photoconductivity gain; hence, the nanowires are favorable for photosensor devices. The wide spectrum obtained also suggests their extensive applications in numerous fields.