A stable organic sol of solvent-stabilized oxovanadium phthalocynine (VOPc) nanoparticles with excellent photoconductivity was successfully prepared by ultrasonificating a prepared nanoscopic VOPc powder in1,2-dichloroethane (C(2)H(4)Cl(2)) without any additive. These solvent-stabilized VOPc nanoparticles have a size distribution from 2 to 20 nm with an average diameter of 4.6 nm. The VOPc concentration of these organic sols could be as high as 100 g/L. The nanoscopic VOPc particles were well-dispersed in an insulating polycarbonate (PC) resin, resulting in single-layered photoreceptors with high surface charge durability in the dark and excellent photoconductivity. Based on the light-assisted scanning tunneling microscopy (STM) measurements, the charge transport mechanism of these photoreceptors was ascribed to light-induced enhancement of electron tunneling through the VOPc-nanoparticle/insulator junctions.