Cobalt Tungsten Oxide Thin Films Prepared by RF-Sputter for Photosensor

This study reports the synthesis and characterization of nonstoichiometric nanocrystalline Co2.59W0.41O4 thin film by the radio frequency (RF)-sputter technique suitable for photosensor applications. The photoconductive characteristics of Co2.59W0.41O4 thin film are investigated by fabricating a sandwich-structure device of p(+)Si/Co2.59W0.41O4 thin film/indium tin oxide with Schottky barriers. The device characteristics including responsivity, light intensity response, and time response are studied. It is found that Co2.59W0.41O4 thin film exhibits good absorption (absorption coefficient approximate to 10(4) cm(-1) in visible light spectrum), relatively high responsivity (R-res = 5.427 A W-1), and fast photoresponse time including rise time (t(r)) = 81.04 ms and fall time (t(f)) = 80.67 ms. Hence, the Co2.59W0.41O4 thin film is favorable for potential photosensor applications.