Surface patterning in Ge-Se amorphous layers

Compositional and fabrication method dependences of laser-induced geometrical surface relief formation in Ge-Se amorphous layers were investigated with the aim to determine the possible role of initial conditions in the mechanism and efficiency of optical recording. The results show that pulsed laser deposition has some advantages in composition preservation and surface relief formation in comparison with thermal evaporation for producing layers with high sensitivity and efficiency of surface relief grating formation, especially in layers with Ge24Se76 composition. It was shown that modulation depth of the created surface structures increases with increasing Se content in Ge-Se amorphous chalcogenide layers. Thermal annealing has essential influence on the recording parameters, enabling additional insight into the possible mechanisms of light induced surface patterning in this type of light-sensitive amorphous chalcogenides. Raman spectroscopy was used to identify local structure of produced surface patterns. (C) 2016 Elsevier B.V. All rights reserved.