Electrical and optical properties of epitaxial binary and ternary GeTe-Sb2Te3 alloys
Electrical and optical properties of epitaxial binary and ternary GeTe-Sb2Te3 alloys
复制标题
外延二元和三元GeTe-Sb2Te3合金的电学和光学性能
DOI：
10.1038/s41598-018-23221-9
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发表时间：
2018
影响因子：
4.6
通讯作者：
R. Calarco
中科院分区：
文献类型：
--
作者：
J. Boschker;X. Lü;V. Bragaglia;Ruining Wang;H. Grahn;R. Calarco
相变材料如伪二元GeTe-Sb2Te3（GST）合金是现有和新兴技术的重要组成部分。本文研究了α-GeTe、Ge2Sb2Te5 （GST225）和Sb2Te3外延相变材料的电学和光学性质。温度相关的霍尔测量显示，sb2te3中空穴浓度随温度升高而降低，这归因于晶格膨胀，导致电阻率非线性增加，这在GST225中也观察到。室温傅里叶变换红外光谱表明α-GeTe和GST225在能隙内存在电子态。我们得出结论，这些电子态是由于这两种材料内部的空位团簇造成的。所得结果揭示了相变材料的基本特性，如高介电常数和持久的光电导率，并有可能包括在器件模拟中。
Phase change materials such as pseudobinary GeTe-Sb2Te3(GST) alloys are an essential part of existing and emerging technologies. Here, we investigate the electrical and optical properties of epitaxial phase change materials: α-GeTe, Ge2Sb2Te5 (GST225), and Sb2Te3. Temperature-dependent Hall measurements reveal a reduction of the hole concentration with increasing temperature in Sb2Te3that is attributed to lattice expansion, resulting in a non-linear increase of the resistivity that is also observed in GST225. Fourier transform infrared spectroscopy at room temperature demonstrates the presence of electronic states within the energy gap for α-GeTe and GST225. We conclude that these electronic states are due to vacancy clusters inside these two materials. The obtained results shed new light on the fundamental properties of phase change materials such as the high dielectric constant and persistent photoconductivity and have the potential to be included in device simulations.