Role of hydrogen in CdTe–Mn thin film bilayer structure

A bilayer thin film of diluted magnetic semiconductor CdTe–Mn is prepared using thermal evaporation method in Hind High Vacuum system at base pressure of 10−5 Torr. The samples are annealed in atmospheric condition at constant temperature of 400 °C for 1 h. Then the hydrogen gas is introduced at different pressure (0–45 psi) for 30 min to hydrogenate these films at room temperature. The optical band gaps of CdTe–Mn bilayer thin films are found to increase with increasing pressure of hydrogen. Therefore it may be suggested that optical band gap can be tailored by introducing hydrogen in CdTe–Mn bilayer thin film. Raman spectra of these samples shows increasing intensity of peaks with hydrogenation and one predominant peak is observed at 336.47 cm−1 that shows the clear evidence of presence of hydrogen in sampled at room temperature. The optical micrographs of these samples show morphological variations due to the hydrogenation.