GaAs纳米线阵列光阴极制备机理及其光谱响应仿真

发布时间：2018-05-10 12:36

本文选题：砷化镓纳米线阵列 + 感应耦合等离子刻蚀　；参考：《东华理工大学》2015年硕士论文

【摘要】：砷化镓(GaAs)纳米线阵列负电子亲和势光阴极因其较高的量子效率,较低的暗电流,良好的长波响应,禁带宽度较窄等特点,成为最有前景的光电发射材料之一,广泛应用在微光夜视,高能光电倍增管等领域,将有机会成为下一代电子加速器电子源。近些年国内外对GaAs光阴极薄膜结构的优化和改进已经进行了大量的研究,同时在纳米线阵列结构的特性研究方面也取得了重大的进展,但是对GaAs纳米线阵列光阴极的研究工作还鲜有报道。基于此,本文对GaAs纳米线阵列光阴极制备工艺及优化,性能表征测试,理论模型仿真等方向展开研究。本文采用感应耦合等离子(ICP)刻蚀法制备GaAs纳米线阵列、变组分AlGaAs纳米线阵列,分析ICP刻蚀法制备GaAs纳米线阵列顶部出现剥离现象的原因,并对制备工艺进行了优化;利用扫描电子显微镜,微区光致发光谱,漫反射谱等研究了GaAs纳米线阵列光阴极的光学特性,发现其反射率远低于薄膜材料结构,光的“捕获效应”明显。GaAs纳米线阵列光阴极微区光致发光谱的波峰像近红外波段偏移,表明其结构的禁带宽度变窄,对长波吸收更好。在实验的基础上,针对GaAs纳米线阵列光阴极的性能表征测试,根据Spicer提出的“三步走”光电发射模型,建立GaAs纳米线阵列光阴极的光电发射模型,通过三维仿真软件,对其进行理论分析,研究入射光的角度,入射光的波长,纳米线直径对GaAs纳米线阵列光阴极的影响。仿真结果表明随着入射光与垂直方向夹角的增大,GaAs纳米线阵列光阴极的光谱响应先增大后减小,这个特性与薄膜结构有很大的不同,而且GaAs纳米线阵列光阴极具有比薄膜材料更高的光谱效应。
[Abstract]:Because of its high quantum efficiency, low dark current, good long wave response and narrow band gap, GaAs nanowire array photocathode has become one of the most promising photoemission materials. Widely used in low-light night vision, high-energy photomultiplier tubes and other fields, there will be a chance to become the next generation electron accelerator electron source. In recent years, a great deal of research has been done on the optimization and improvement of GaAs thin film structure, and great progress has been made in the study of the characteristics of nanowire arrays. However, there are few reports on the photocathode of GaAs nanowire arrays. Based on this, the preparation process and optimization of photocathode for GaAs nanowire array, performance characterization test, theoretical model simulation and so on are studied in this paper. In this paper, GaAs nanowire arrays and AlGaAs nanowire arrays with variable components were prepared by inductively coupled plasma etching. The causes of the peeling at the top of GaAs nanowire arrays prepared by ICP etching were analyzed, and the preparation process was optimized. The optical properties of GaAs nanowire array photocathode were studied by scanning electron microscope, microphotoluminescence and diffuse reflectance spectra. The reflectivity of the photocathode was much lower than that of the thin film structure. The "capture effect" of light is obvious. The near infrared band migration of photoluminescence spectrum in photocathode microregion of GaAs nanowire array shows that the band gap of the structure becomes narrower and the absorption of long wave is better. Based on the experiment, according to the three-step photoemission model proposed by Spicer, the photoemission model of GaAs nanowire array photocathode is established according to the performance characterization test of GaAs nanowire array photocathode, and the three-dimensional simulation software is used to simulate the photoemission model of GaAs nanowire array photocathode. The influence of the angle of incident light, the wavelength of incident light and the diameter of nanowire on the photocathode of GaAs nanowire array is studied. The simulation results show that the spectral response of photocathode of GaAs nanowire array first increases and then decreases with the increase of the angle between incident light and vertical direction, which is very different from the structure of the thin film. Moreover, the photocathode of GaAs nanowire array has higher spectral effect than the thin film material.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ133.51;TB383.1

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