Au电极厚度对MgZnO紫外探测器性能的影响

	Au电极厚度对MgZnO紫外探测器性能的影响
	孙华山
学位类型	硕士
导师	申德振
	2014-11
学位授予单位	中国科学院大学
学位专业	凝聚态物理
关键词	Mgzno薄膜紫外探测器 Au电极厚度
摘要	ZnO基半导体材料具有缺陷密度低，抗辐射能力强，环境友好等诸多优点，且可通过Mg的掺入使其禁带宽度从3.3 eV到7.8 eV连续可调，被认为是制备日盲和可见盲紫外探测器的理想材料之一。截至目前，人们已通过不同方法制备了各种结构的MgZnO紫外探测器，而如何提高器件的性能一直都是各国科研人员所不断追求的。众所周知，金属电极是半导体紫外光电探测器件的一个重要组成部分，通过金属电极可以对器件施加偏压并收集电信号，但是，金属电极对紫外光有着强烈的吸收，会降低器件的外量子效率。因此，电极的材料，结构以及厚度的不同都会引起器件性能的巨大差异。一般来说，在材料和结构确定的情况下，电极的厚度会影响其透光性和导电性（薄的电极透光性好但导电性不好，而厚的电极则刚好相反），进而影响器件的性能。因此，通过优化金属电极的厚度可以有效改善紫外探测器件的性能。本论文在总结了MgZnO薄膜及其探测器件的研究现状的基础上，制备了不同Au电极厚度的MgZnO紫外探测器件，旨在探索出最佳电极厚度，主要研究工作如下：一、使用分子束外延生长（MBE）设备，通过Zn源和Mg源温度的调控，制备了不同Mg组分的MgZnO合金薄膜，并研究了其结构和光学特性，为实现MgZnO紫外探测器件提供材料基础。二、使用离子溅射设备，在所制备的MgZnO薄膜上制备了Au电极，并实现了Au-MgZnO-Au结构的紫外探测器。通过调整溅射时间，制备了具有不同Au电极厚度的样品。测试了样品的光谱响应曲线，暗电流等数据。当Au电极厚度从0~32 nm变化时，器件光响应度随金属厚度增加，呈现先增高后降低的变化规律，当厚度为28 nm时，光响应度达到最高值。
其他摘要	ZnO has been recognized as one of the most promising candidates for solar- or visible-blind UV photodetectors due to their special properties, such as low defect density, high radiation hardness, environment friendly, and continuous tunable band gap (3.3 eV-7.8 eV) by the incorporation of Mg. Till now, many kinds of MgZnO UV detectors have been fabricated trough different methods, and most studies have been concentrated on how to improve the performance of the detectors. As is well known, the metal electrode is an important part of semiconductor ultraviolet detectors, through which the bias voltage can be applied to the device and the electric signals can be collected. However, the metal electrode, which has a strong absorption of ultraviolet light, will reduce the external quantum efficiency of the device. Thus, the material, the structure and the thickness of electrode would have significant effects on the devices’ performance. For a given electrode geometry and material, the transmittance and the conductivity of the electrode are strongly dependent on the electrode thickness, i.e. thinner electrode has higher transmittance and lower electrical conductivity, while thicker one is just the opposite. Therefore, choosing the appropriate thickness of the metal electrode is an effective method to improve the performance of UV detectors. Based on the research status of MgZnO films and detectors, MgZnO UV photodetectors with different Au electrode thicknesses have been demonstrated and investigated in this thesis to find out the optimal electrode thickness. The main research works are as follows: 1. We fabricated MgZnO films with different Mg fractions by tuning the temperature of Mg and Zn sources using the molecular beam epitaxy (MBE) equipment, and the structural and optical properties of MgZnO films have been investigated. This would provide the material foundation for the realization of MgZnO UV detector. 2. Au electrodes were prepared on the MgZnO thin films using the ion sputtering equipment to realize the Au-MgZnO-Au structure UV photodetectors. By adjusting the sputtering time, the devices with different Au electrode thicknesses can be demonstrated. We measured the response spectra, the dark current, and so on. With increasing the Au electrode thickness from 0 to 32 nm, the responsivity of the MgZnO UV photodetectors increases firstly and then decreases. And when the Au electrode thickness is 28 nm, the responsivity reaches the maximum value.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/44687
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	孙华山. Au电极厚度对MgZnO紫外探测器性能的影响[D]. 中国科学院大学,2014.

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