title: Oxygen Tuned Local Structure and Phase-Change Performance of Germanium Telluride.
abstract: The effect of oxygen on the local structure of Ge atoms in GeTe-O materials has been investigated. Oxygen leads to a significant modification to the vibrational modes of Ge octahedra, which results from a decrease in its coordination. We find that a defective octahedral Ge network is the crucial fingerprint for rapid and reversible structural transitions in GeTe-based phase change materials. The appearance of oxide Raman modes confirms phase separation into GeO and TeO at high level O doping. Counterintuitively, despite the increase in crystallization temperature of oxygen doped GeTe-O phase change materials, when GeTe-O materials are used in electrical phase change memory cells, the electrical switching energy is lower than the pure GeTe material. This switching energy reduction is ascribed to the smaller change in volume, and therefore smaller enthalpy change, for the oxygen doped GeTe materials.
authors.affiliation: ACTA Lab, Singapore University of Technology and Design , 8 Somapah Road, 487372, Singapore.
authors.forename: Xilin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Institute of Chemical and Engineering Sciences, A*STAR , 1 Pesek Road, Jurong Island 627833, Singapore.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Du
authors.affiliation: ACTA Lab, Singapore University of Technology and Design , 8 Somapah Road, 487372, Singapore.
authors.forename: Jitendra K
authors.initials: JK
authors.lastname: Behera
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences , 200050 Shanghai, China.
authors.forename: Liangcai
authors.initials: L
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences , 200050 Shanghai, China.
authors.forename: Zhitang
authors.initials: Z
authors.lastname: Song
authors.affiliation: ACTA Lab, Singapore University of Technology and Design , 8 Somapah Road, 487372, Singapore.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Simpson
keywords: octahedral structure; oxygen doping; phase change material; switching energy; vibration modes