On the properties of GeTe/Sb2Te3 superlattice-like structure for phase-change optical recording

摘要

GeTe/Sb2Te3 superlattice-like (SLL) structure, consisting of alternating thin layers of two different phase-change materials, GeTe and Sb2Te3, were grown by magnetron sputtering technique on silicon (100) and polycarbonate substrates. The optical and thermal properties as well as the structural characterization of the film were investigated. Ellipsometric spectroscopy showed that the optical constants could be modulated by changing the ratio and period of the SLL structure in the range of 400 to 800 nm. Differential scanning calorimeter (DSC) measurements indicated SLL structure to have lower activation energy than that of the mGeTe-nSb2Te3 pseudobinary with the same ratio. X-ray diffraction (XRD) analysis shows that Ge2Sb2Te5 was formed at the GeTe/Sb2Te3 interface after laser-induced crystallization.