Structural , Morphological and Optical Studies of As-Prepared and Annealed Cadmium Doped

The present study is undertaken in order to investigate the influence of addition of cadmium (Cd) with decreasing at.wt. % of Tellurium (Te) at constant at wt% of Selenium (Se) on the optical properties of the Te90-xSe10Cdx (x = 0, 10, 20). Optical Studies of the metal doped chalcogenide prepared by melt quenching method from 99.999% pure elements has been reported. XRD pattern reveals that asprepared and thermally annealed chalcogenide alloys show polycrystalline nature and a combination of hexagonal and cubic phase. Average crystal size observed by Scherrer’s formula for as-prepared and thermally annealed sample S1, S2, S3 of Te90-xSe10Cdx (x=0, 10, 20) are 22.83, 33.86 ,29.58 nm and 21.51,49.27,46.34 nm respectively. FESEM images of the sample S1, S2, and S3 are uniform which shows the presence of some micro-crystallites of the synthesised material. Spectral dependence of the absorption spectra recorded in the range of 200 – 1000 nm for as-prepared and thermally annealed samples in normal wavelength scanning mode is shown by UV-Visible spectroscopy. Crystal size and optical band gap(Eg) of the as-prepared and thermally annealed sample increases while dislocation density, absorption coefficient of each sample decrease with increasing Cd% in the sample. The luminescence intensity of as-prepared sample S3 (20% of Cd) is much more than its annealed sample at 330 nm excitation wavelength.