On the density of states of germanium telluride
On the density of states of germanium telluride
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DOI：
10.1063/1.4768725
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发表时间：
2012-12
影响因子：
3.2
通讯作者：
C. Longeaud;J. Luckas;D. Krebs;R. Carius;J. Klomfaß;M. Wuttig
中科院分区：
文献类型：
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作者：
C. Longeaud;J. Luckas;D. Krebs;R. Carius;J. Klomfaß;M. Wuttig
碲化锗（GeTe）是研究最多的相变材料之一。令人惊讶的是，人们对其带隙中的态密度（DOS）知之甚少。本文从实验和理论两方面研究了非晶GeTe薄膜的钝化特性。我们提出了该DOS的模型以及该材料的一些传输参数的估计。用溅射法制备了非晶态碲薄膜。它们的暗电导率和光电导率已被测量为温度的函数。利用调制光电流技术探测了它们的DOS，并在室温下用光热偏转光谱研究了它们的吸收。在适当的传输参数设置和DOS选择下，通过数值计算再现了实验结果。这些数据为进一步研究DOS对样品电阻老化（“电阻漂移”）的影响奠定了良好的基础。
Germanium telluride (GeTe) is one of the most studied phase change materials. Surprisingly, only little is known about the density of states (DOS) in its band gap. In this paper, the DOS of amorphous GeTe films is investigated both experimentally and theoretically. We propose a model for this DOS as well as estimates of some of the transport parameters of this material. Thin films of amorphous GeTe have been deposited by sputtering. Their dark and photoconductivity have been measured as a function of temperature. By means of the modulated photocurrent technique their DOS was probed, while their absorption was investigated by photothermal deflection spectroscopy at room temperature. Numerical calculations were employed to reproduce the experimental results with a proper set of transport parameters and choice of DOS. These data constitute a good basis for further study on the influence of the DOS on the aging of the sample resistance (“resistance drift”).