Characterization of pure and Cu doped V2O5 nanostructures and their Cu:V2O5/p-Si photodiode applications

In this study, a wet chemical approach was exploited to synthesis of Cu-doped V2O5 (CVO) nanostructures with different doping concentrations of Cu at 5, 10, and 15%. The structural analysis confirms that samples annealed at 600oC rehabilitated to monoclinic V2O5. The surface morphology and nanostructure were studied by SEM and TEM analysis. The presence of various elements (Cu, V & O) and their compositions were confirmed using EDS and XPS measurements. The photoluminescence spectrum reveals a strong blue emission at 418 nm is ascribed to the electronic transition from vanadium interstitial to the valence band. Further, we fabricated the junction diodes by the nebulizer spray depositing CVO nanostructures in a colloidal form on the p-Si substrate at 150oC. Depending on the applied voltage and Cu doping level the rectifying behavior with a high rectification ratio (RR) was observed from the I-V characteristics of studied diodes. Inclusively, a V2O5 with substitution of Cu at.15% has significantly enhanced the photoresponse time and current density (J=4.19x10-4A/cm2).