Band Gap Engineering of Ternary Nanostructured Thin Films for Photosensor Application CdS_0.8Se_0.2

Ternary nanostructured CdS_0.8Se_0.2 thin film was prepared on to glass substrate by a simple and economical soft chemical route at 50°C at room temperature. The as-grown films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), optical and electrical measurements. The XRD patterns reveal that CdS_0.8Se_0.2 thin films have hexagonal mixed nanostructure as compare to CdS and CdSe thin films. SEM images showed uniform deposition of the material over the entire glass substrate. The optical study reveals shift in the absorption edge towards the higher wavelengths, i.e. the band gap decreases as compared to CdS. Electrical resistivity shows semiconducting behavior and activation energy varies as compared to CdS and CdSe. I-V measurement of CdS_0.8Se_0.2 thin film under dark and illumination conditions (60W) was measured. Increase in photoconductivity is observed, suggesting its applicability in photosensors devices.