Study of the Ge20Te80-xSex glassy structures by combining solid state NMR, vibrational spectroscopies and DFT modelling

ABSTRACT The glassy ternary system Ge-Te-Se is currently receiving an increased attention due to its extended range of transmission in the infrared opening the way to various potential applications in photonics. In this study, a multi-techniques approach combining solid-state NMR, Raman and infrared spectroscopies and DFT calculations provides insight into the organization of the GeSe4-GeTe4 glassy network and allows to clarify a whole structural description of the glassy system. A particular attention is devoted to the presence of mixed GeTe8-xSex structural units and to the type of interconnections forming the glass networks. Such experimental/theoretical approach is provided both for the selenium and the tellurium rich part of the glassy system.