MOCVD of Bi2Te3, Sb2Te3 and their superlattice structures for thin-film thermoelectric applications
MOCVD of Bi2Te3, Sb2Te3 and their superlattice structures for thin-film thermoelectric applications
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DOI：
10.1016/s0022-0248(96)00656-2
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发表时间：
1997-01-01
影响因子：
1.8
通讯作者：
ElMasry, N
中科院分区：
文献类型：
--
作者：
Venkatasubramanian, R;Colpitts, T;ElMasry, N
本文讨论了Bi_2Te_3、Sb_2Te_3的MOCVD特性及其超晶格结构。我们生长的c取向的薄膜上的六角蓝宝石和费砷化镓衬底，镜面形态和偶尔堆垛层错。X射线衍射和低能电子衍射（LEED）证实了单晶。通过X射线光电子能谱（WS）和卢瑟福背散射（Rutherford backscattering）证实了薄膜的化学计量比（Bi：Te = 2：3，Sb：Te = 2：3）。我们还尝试在Bi 2 Te 3/Sb 2 Te 3材料系统中生长短周期（类似于10至80埃）超晶格结构。X射线衍射数据表明这些层状结构的质量。这些材料中的化学键合的性质，沿着生长方向，为获得突然的接口提供的优点进行了讨论。讨论了MOCVD生长的p型Bi_2Te_3/Sb_2Te_3结构的电输运性质和其它热电性质，包括热导率和塞贝克系数。平行于超晶格界面平面测量的超晶格结构的性能参数（称为品质因数）的初始结果明显高于常规的块状材料。这些初步结果表明，基于MOCVD的材料技术在高性能薄膜热电制冷方面具有巨大的潜力。
The characteristics of metalorganic chemical vapor deposition (MOCVD) of Bi2Te3, Sb2Te3 and their superlattice structures are discussed in this paper. We have grown c-oriented films on both hexagonal sapphire and fee GaAs substrates, with specular morphology and occasional stacking faults. Single crystallinity was confirmed by X-ray diffraction and low-energy electron diffraction (LEED). The stoichiometry (Bi:Te = 2:3, Sb:Te = 2:3) of the films were confirmed by X-ray photo-emission spectroscopy (WS) and Rutherford back-scattering. We have also attempted to grow short-period (similar to 10 to 80 Angstrom) superlattice structures in the Bi2Te3/Sb2Te3 materials system. X-ray diffraction data indicating the quality of these layered structures is presented. The advantages offered by the nature of chemical bonding in these materials, along the growth direction, for obtaining abrupt interfaces is discussed. The electrical transport properties of the MOCVD-grown p-type Bi2Te3/Sb2Te3 structures and other thermoelectric properties including thermal conductivity and Seebeck coefficient are discussed. The initial results on the performance parameter known as figure-of-merit of the superlattice structures, measured parallel to the plane of the superlattice interfaces, are significantly higher than in conventional bulk materials. These initial results suggest a significant potential for MOCVD-based materials technology for high-performance, thin-film, thermoelectric refrigeration.