Non-stoichiometric W18O49−xSx nanowires for wide spectrum photosensors with high internal gain

Abstract

This study reports successful synthesis of non-stoichiometric single-crystal W₁₈O_49−xS_x nanowires for photosensors with a high absorption rate (>83%) across a wide spectrum (300–2000 nm), a high internal gain (G = 10⁶–10⁷) 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 W₁₈O_49−xS_x nanowires was studied. The surface-to-volume ratio and non-stoichiometric material of W₁₈O_49−xS_x 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.