Evaluation of cadmium telluride (CdTe) thin films grown at different annealing temperatures for efficient terahertz generation

The paper reports the terahertz generation from polycrystalline CdTe thin films using 800 nm wavelength of 35 fs pulse duration at 1 kHz repetition rate obtained from Ti: sapphire laser amplifier. These films were deposited by thermal evaporation on a glass substrate and annealed at 200 and 300°C. The structural was investigated by XRD technique. Absorbance and transmittance were recorded in the wavelength (300- 800 nm). Optical studies showed that the optical energy gap decreases with increasing annealing temperatures. The results show that the film annealed at 200°C shows the highest generation of the order of 88 nW.