Abstract: The optical absorption properties of phase-change optical recording thin films subjected to various initialization conditions were investigated. The effects of initialization power and velocity on optical constants of the Ge2Sb2Te5 thin films were also studied. The energy gap of Ge2Sb2Te5 thin films subjected to various initialization conditions was also obtained. It was found that the optical energy gap of the Ge2Sb2Te5 thin films increased with either increasing initialization laser power or decreasing initialization velocity, with peak of 0.908 eV at laser power of 1000 mW or initialization velocity of 4.0 m/s, but the continued increasing initialization laser power or decreasing initialization velocity resulted in the decrease of the optical energy gap. The change of the optical energy gap was discussed on the basis of amorphous crystalline transformation.

Key words: Phase transformation, Optical recording, Ge2Sb2Te5, Optical absorption, Energy