Novel syntheses of wide-band gap semiconducting Cdx Znx-1 Co2O4 of spinel nanostructure: Characterization and optical properties

Abstract Cadmium doped zinc cobaltite spinel structure in the form of CdxZnx-1Co₂O₄ (0 ≤ x ≤ 1) are synthesized by sol-gel method. A good crystallinity of the ZnCo₂O₄ and its dopants samples are indicated by the sharpness and strong peaks of X-ray diffraction patterns. The particle size is independent of the ratio of incorporated Cd into the ZnCo₂O₄ matrix. The FT-IR transmission spectrum of each Cdx Zn1-xCo₂O₄ complex shows two strong vibration peaks that are ascribed to the spinel structure's octahedral and tetrahedral. The occurrence of light absorption by Cdx Znx-1 Co₂O₄ is due to the photoexcitation of electrons from O 2p to Co 3d transitions and d-d transition of Co 3d. The obtained values of the optical band gap (Eg) for Cdx Zn1-xCo₂O₄ varies from 2.93 eV for ZnCo₂O₄ (x = 0) to 2.15 eV for CdCo₂O₄ (x = 1).