Modification of structural and optical properties of Ag doped Ge_2Sb_2Te_5 thin films using swift heavy ion irradiation

摘要

Swift heavy ion irradiation is performed on 5% Ag doped Ge_2Sb_2Te_5 (GST) thin films to observe the changes in structural and optical properties. The thin films have been irradiated with Ag~(9+) ions having 120 MeV energy. It has been observed that irradiation does not leads to phase change and the red shift observed in Raman spectra indicates the weakening of bond strength. Moreover, reduction in bandgap is also observed as an effect of increasing irradiation dose. These results indicate that the irradiation with high energy ions introduces defects in the thin films which may lead to local generation of crystal nuclei. These crystal nuclei may be responsible for the modification of optical and electrical properties in these films.