Silicon-doping influence on the crystalline, surface and optical features of cadmium oxide films deposited by sol-gel spin route

This is the first study on Si-contributed CdO films fabricated via sol-gel process. Si-doping impact on the crystalline, topographic and optical qualities of cadmium oxide has been searched with XRD, SEM, AFM and UV/vis spectrophotometer. The whole films were polycrystalline with (111) preferential direction and the crystalline degree of CdO depended on Si-contribution effect. The crystallite size of undoped-CdO incessantly decreased with Si-content, however dislocation density increased with Si-level. The spherical CdO granules were nanoscale and their sizes varied between 20-170 nm. The RMS roughness values of films changed between 5.84 nm-40.5 nm. The optical gap value of undoped-CdO continuously declined from 2.59 eV to 2.39 eV with increasing Si-content, while the Urbach energy increased from 350 meV to 468 meV with Si-level. These results reveal that the level of Si-doping affect the features of cadmium oxide.