Influence of doping on the structure and optical characteristics of Ge 2 Sb 2 Te 5 amorphous films

The influence of doping on the structural and optical characteristics of Ge2Sb2Te amorphous thin films has been determined with micro-Raman scattering spectroscopy and a variable incident angle spectroscopic ellipsometer (VASE). The measured Raman spectra revealed the existence of two overlapping bands B2 near 130 cm-1 and C1 near 150 cm-1. The additional small features in the responses were revealed in the range less than 100 cm-1. Suggest that micro-Raman scattering spectroscopy can be used to study phase change materials through local structural information. The distinct changes in refractive index and extinction coefficient of Ge2Sb2Te amorphous films due to doping were revealed in the visible range. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)