Origin of Band Modulation in GeTe-Rich Ge–Sb–Te Thin Film

Abstract

Germanium tellurides and their pseudobinary compounds offer interesting properties that are important in thermoelectric and phase-change applications. Despite being a class of materials under scrutiny since its discovery, unique properties and functionalities have kept on emerging in recent years. In this work, we observed another unique property of Ge−Sb−Te (GST) thin film that can be beneficial in its development for thermoelectric applications. A rapid heating and quenching process of the GST film resulted in a metastable rock-salt cubic structure, exhibiting a unique electronic-transition-like behavior. Above the transition temperature at 150 °C, we observed a temperature-induced band modulation, corroborated with changes in its effective mass and valence band position that leads to favorable electronic and thermoelectric properties. Charge transfer between Sb and Te occurred, accompanied by a distorted cubic-to-cubic structural change. The interplay of the electronic and lattice structure born out of the composition and phase of the Ge−Sb−Te thin film opened up the possibility for the future of thermoelectric devices.

Study of Ge‐Sb‐Te Superlattice Structure Based on Topological Descriptors

“…Cationic elements, such as group IVA (Sn and Pb), group IIIA (In and Ga), and transition metals are used to construct these GST alloy [47]. The physicochemical properties of Ge-Sb-Te (GST) can be utilized for sensing, as well as in thermoelectric, nonvolatile RAM and face change properties [48,49]. This can help to improve the bandgap energy of GST.…”

On computation of some open and closed neighbourhood degree sum-based topological indices for metal-insulator transition super lattice network

“…The physico-chemical characteristics are helpful for sensing, in nonvolatile RAM, thermoelectric properties and face changing features to increase the bandgap energy of Ge-Sb-Te (GST) [19,20]. Phase Change Material (P CM ) properties of Ge − Sb − T e (GST ) complex with a group of chalcogenides are promising technology and well known for many years [21,22].…”