Photocurrent enhancement of SnO_2 nanowires through Au-nanoparticles decoration

It is found that the sensitivity of photoresponse of SnO(2) nanowires can be enhanced by metallic particles decoration. The underlying mechanism is attributed to the formation of the Schottky junction on nanowires surface in the vicinity of metallic nanoparticles. The increment in the barrier height and width of space charge region due to the existence of Schottky junction increases the surface electric field and enhances the spatial separation effect, which then prolongs the lifetime of photoinduced electron and consequently increases the photoresponse gain. The result shown here provides an alternative route for enhancing the photoresponse of semiconductor nanostructures, which should be useful for creating highly sensitive photodetectors.