Near ultraviolet photodetector fabricated from polyvinyl-alcohol coated In2O3 nanoparticles

A near ultraviolet (UV) photodetector is fabricated from colloidal In2O3 nanoparticles coated with polyvinyl-alcohol (PVA). The device exhibits lower dark current and higher responsivity compared with a photodetector fabricated from uncoated In2O3 nanoparticles. The rise and fall time of the PVA coated photodetector is about 500 s and 1600 s, respectively, one half of the uncoated device. The faster response time of the PVA enhanced photodetector is due to surface passivation which reduces the surface defects while enhancing desorption of oxygen from the nanoparticle surface, thus increasing free carrier concentration.