title: Enhanced Crystallization Behaviors of Silicon-Doped Sb2Te Films: Optical Evidences.
abstract: The optical properties and structural variations of silicon (Si) doped Sb2Te (SST) films as functions of temperature (210-620 K) and Si concentration (0-33%) have been investigated by the means of temperature dependent Raman scattering and spectroscopic ellipsometry experiments. Based upon the changes in Raman phonon modes and dielectric functions, it can be concluded that the temperature ranges for intermediates and transition states are estimated to 150, 120, 90, and 0 K, corresponding to ST, SST25%, SST28%, and SST33% films, respectively. The phenomenon also can be summarized by the thermal evolutions of interband electronic transition energies (En) and partial spectral weight integral (I). The disappearance of intermediate (INT) state for SST33% film between amorphous (AM) and hexagonal (HEX) phases can be attributed to the acceleratory crystallization of HEX phase by Si introduction. It illustrates that the risk of phase separation (Sb and Te) during the cyclic phase-change processes decreases with the increasing Si concentration. The enhanced crystallization behaviors can optimize the data retention ability and the long term stability of ST by Si doping, which are important indicators for phase change materials. The performance improvement has been analyzed qualitatively from the optical perspective.
authors.affiliation: Department of Electronic Engineering, East China Normal University, Shanghai 200241, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Guo
authors.affiliation: Department of Electronic Engineering, East China Normal University, Shanghai 200241, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Electronic Engineering, East China Normal University, Shanghai 200241, China.
authors.forename: Jinzhong
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Electronic Engineering, East China Normal University, Shanghai 200241, China.
authors.forename: Zhigao
authors.initials: Z
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Liangcai
authors.initials: L
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Zhitang
authors.initials: Z
authors.lastname: Song
authors.affiliation: Department of Electronic Engineering, East China Normal University, Shanghai 200241, China.
authors.forename: Junhao
authors.initials: J
authors.lastname: Chu