电化学原子层外延法制备碲化铋薄膜

Preparation of Bismuth Telluride Thin Film by Electrochemical Atomic Layer Epitaxy

研究了冷压银衬底上铋和碲的欠电位沉积薄层电化学行为。分析了最初铋欠电位沉积在碲覆盖的冷压银表面和碲欠电位沉积在铋覆盖的冷压银表面的欠电位转移伏安特性。结果证实,这种转移特性符合欠电位动力学机制。采用一个自动式电化学薄层流沉积系统,通过交替沉积碲元素和铋元素制备了碲化铋薄膜。XRD测试显示,沉积物是B i2Te3。EDX定量分析给出铋与碲的元素化学计量比是2∶3,与XRD结果一致。沉积物电子探针显微分析显示一个网格结构,可能与冷压银衬底的表面缺陷及银和B i2Te3的晶格错配有关。

Thin-layer electrochemical studies of the underpotential deposition （UPD） of Bi and Te on cold rolled silver substrate have been performed. The vohammetric analysis of the underpotential shift demonstrated that the initial Te UPD on Bi-covered Ag and Bi UPD on Te-covered Ag fitted UPD dynamics mechanism. Thin film of bismuth telluride was formed by alternately depositing Te and Bi vht an automated flow deposition system. X-ray diffraction indicated the deposits of Bi2Te3. EDX quantitative analysis gave a 2：3 stoichiometric ratio of Bi to Te, which was consistent with XRD result. Electron probe microanalysis of the deposits showed a network structure that resulted from the surface defects of the cold rolled Ag substrate and the lattice mismatch between substrate and deposit.