Photosensitivity of pulsed laser deposited Ge-Sb-Se thin films

Pulsed laser deposition was used to prepare amorphous thin films from (GeSe sub(2)) sub(100-x) (Sb sub(2)Se sub(3)) sub(x) system, where x is varying from 0 to 60. Fabricated films present a good morphology with no cracks nor breaks and relatively low roughness. To study their photosensitivity under irradiation with energy close to band gap, a comparison of their optical properties (refractive index and band gap energy) before and after irradiation is performed in both, as-deposited and annealed states. In linear regime, annealed films seem to be photostable when x> or =30. In nonlinear regime, highest photoinduced threshold intensity values were found for films with x = 10,16.7 and x = 30, 40. Thus, the highest photostability in both, linear and nonlinear regimes of irradiation, was observed for layers with x = 30 and 40. Finally, the structure of the films is discussed based on Raman scattering spectroscopy results.