用于光伏应用的溶胶-凝胶法制备Cd掺杂ZnO薄膜的表征

Zinc oxide (ZnO) thin films found to have various potential roles in optoelectronic and electronic device applications. The properties of ZnO thin films got to vary and could be improvised through doping. Cadmium (Cd) was chosen for the present study among the series of different elements adopted for doping as it was less reported in earlier studies. Cadmium was chosen as a dopant for ZnO not merely due to its limited reporting in earlier studies, but because of its unique potential to tailor the optical and electronic properties of ZnO in ways that are highly relevant for optoelectronic and TCO applications. Cd 2 ⁺ has a larger ionic radius than Zn 2 ⁺ and forms a binary oxide (CdO) with a much narrower bandgap (~ 2.2 eV), compared to ZnO (~ 3.3 eV).Thin films were fabricated with varied concentrations of Cd doped with ZnO and studied for its characteristics. The structural properties of coated thin films determined from XRD pattern depicted the crystalline nature of thin films being affected by the doping element (Cd). The transmittance of these films was observed around 80% at visible region. The measured band gap energy of films varies between 3.0 and 3.1 eV. The resistivity of the Cd doped films was measured as 700 MΩ/sq-cm. The emission peaks observed at 740 nm in PL spectra shows the intensity of defect related peak. The aborption bands found at 450 cm −1 in FTIR spectra corresponds to characteristic nature of ZnO. The film morphology analysis by SEM showed closely packed nano rod structure. The present study has been used to check the suitability of Cd as the doping element for ZnO thin films for elements of solar cell.