Effect of laser irradiation on structural and optical properties of thermally evaporated thin films of amorphous Cd5Se95−xZnx

Abstract

Thin films of Cd5Se95−xZnx (x = 0, 2, 4) were deposited by a thermal evaporation technique on glass substrates. These films were irradiated by pulsed laser at different durations of time. Laser irradiation of Cd5Se95−xZnx (x = 0, 2, 4) was accompanied structural changes which in turn leads to the change in optical properties of the material. The X-ray diffraction pattern of Cd5Se95−xZnx (x = 0, 2, 4) shows that the grain size increases due to the addition of Zn and decreases after laser irradiation. It was also found that the value of dislocation density increases after laser irradiation. The surface morphology of laser-irradiated thin films of Cd5Se95−xZnx (x = 0, 2, 4) shows that the disorderness or defects are produced due to laser irradiation. Energy dispersive X-ray spectroscopy confirms the elemental composition of the ternary alloy of Cd5Se95−xZnx (x = 0, 2, 4). The optical constants of Cd5Se95−xZnx (x = 0, 2, 4) were calculated from optical transmission spectra. The value of optical band gap increases after laser irradiation and decreases due to the addition of Zn.