In this study, we investigated Ge2Sb2Te5 (GST225) amorphous thin films doped with Bi, Sn and In, using Raman scattering spectroscopy, to obtain information about structural changes after doping. Such impurities as Bi and Sn were chosen due to their isomorphism with one of the main components; indium is an active dopant for phase change materials. Two main, most intensive bands appeared at 125 and 153 cm−1 in the spectrum of undoped amorphous GST225 thin film. Additional small bands in the range of 80 cm−1 and near 300 cm−1, which disappeared in Raman spectra of crystalline GST225 thin films, were also observed. The obtained peak parameters were found to correlate with the dopant type and concentration. The concentration dependencies are not monotonic, and this fact indicates different incorporation mechanisms for different dopant levels

The structure of binary ${\text{Ge}}_x{\text{Se}}_{100-x}$ chalcogenide glass family $\left(0\le x\le 30\right)$ is determined by high-resolution x-ray photoelectron spectroscopy (XPS). On the basis of compositional dependences of fitting parameters for Ge and Se core level XPS spectra, the ratio between edge- and corner-shared tetrahedra is determined. We find that this ratio for glasses with $20\le x\le 30$ is almost constant with a value same as for the high-temperature crystalline form of ${\text{GeSe}}_2$ .

Over the past 30 years, phase change memory materials based on chalcogenide semiconductors have rapidly developed from laboratory prototypes to materials extensively used as functional layers in various devices. First of all, this concerns compounds of the Ge–Sb–Te system, which can be reasonably considered as full-fledged functional materials. The review presents a current view of the control of properties of phase change memory materials by their chemical and structural modification. Both the existing and prospective applications of these materials are highlighted. The discussion of chemical modification focuses on popular dopants such as bismuth, tin, oxygen and nitrogen and also refractory metals. In the discussion of structural modification, the use of laser radiation is considered in detail. Currently, this is a key trend in increasing the operation speed of devices based on phase change memory materials. Data on the formation of periodic surface structures in these materials are highlighted and it is emphasized that this effect could find application in nanophotonics and optoelectronics in the near future. The bibliography includes 336 references