低维半导体纳米材料的制备、微观结构及其形成机理的研究

发布时间：2018-01-12 06:16

本文关键词：低维半导体纳米材料的制备、微观结构及其形成机理的研究　出处：《青岛大学》2015年硕士论文　论文类型：学位论文

【摘要】：本论文主要对低维半导体纳米材料(零维锗纳米晶、一维磷化铟纳米线)的制备、微观结构与生长机理进行了系统的研究。利用高分辨电子显微学技术,阐明了其生长机理,可为低维半导体纳米材料的制备与应用提供理论基础。本硕士论文共分为四章。第一章首先对低维半导体纳米材料的基本特性、制备方法、表征手段、应用领域等方面进行了综述。第二章通过离子注入法在非晶二氧化硅薄膜制得锗纳米晶,并在高温下(700oC-1100 oC)进行退火处理。研究发现,锗纳米晶的平均尺寸随着退火温度的升高而增加。透射电镜观察发现,在锗纳米晶内部存在面缺陷与线缺陷,并且面缺陷与线缺陷的含量均随退火温度的改变而变化。当退火温度低于1000 oC时,面缺陷含量与退火温度无明显关系,而当退火温度自1000 oC升至1100 oC时,面缺陷含量急剧降低;线缺陷含量则随着退火温度的变化而发生显著变化。此外,通过研究不同温度下锗纳米晶位错的含量与内部的残余应力的关系,发现位错的形成与内应力场的释放存在内在联系。第三章通过固相源化学气相沉积法制备了磷化铟纳米线,利用电子显微学技术对磷化铟纳米线中存在的不同角度的弯曲结构进行了观察,对其生长机理进行了研究。统计发现,在所制备的磷化铟纳米线中,弯曲角度主要集中在70o,90o,110o与170o。对于约70o与110o的弯曲的形成主要是由于纳米线中层错及孪晶的出现所造成的;约90o的弯曲则来自于局部非晶化;约170o弯曲则主要归因于小角晶界的出现。第四章利用透射电子显微镜对磷化铟纳米线中的微观结构进行了研究,发现所制备的磷化铟纳米线具有面心立方结构且存在孪晶缺陷,且孪晶缺陷密度随纳米线直径的增加而增大。该现象主要是由于不同直径的纳米线其催化剂头尺寸不同,导致催化剂中铟的过饱和程度不同。
[Abstract]:In this paper, the preparation, microstructure and growth mechanism of low-dimensional semiconductor nanomaterials (zero-dimensional germanium nanocrystals, one-dimensional indium phosphide nanowires) were studied systematically. The growth mechanism is explained, which can provide a theoretical basis for the preparation and application of low-dimensional semiconductor nanomaterials. This master thesis is divided into four chapters. The first chapter is about the basic characteristics and preparation methods of low-dimensional semiconductor nanomaterials. In chapter 2, germanium nanocrystals were prepared by ion implantation in amorphous silica thin films. The results show that the average size of germanium nanocrystals increases with the increase of annealing temperature. Transmission electron microscopy (TEM) shows that the average size of germanium nanocrystals increases with the increase of annealing temperature. Surface defects and linear defects exist in germanium nanocrystals, and the contents of surface defects and linear defects vary with the annealing temperature, when annealing temperature is less than 1000oC. The surface defect content has no obvious relationship with annealing temperature, but when annealing temperature rises from 1000 OC to 1100 OC, the surface defect content decreases sharply. The content of linear defects changed significantly with the change of annealing temperature. In addition, the relationship between the content of dislocation and the internal residual stress of germanium nanocrystalline at different temperatures was studied. It is found that the formation of dislocation is related to the release of internal stress field. In chapter 3, indium phosphide nanowires were prepared by solid-phase chemical vapor deposition. The bending structure of indium phosphide nanowires at different angles was observed by means of electron microscopy and the growth mechanism was studied. It was found that in the prepared indium phosphide nanowires. The bending angle is mainly concentrated at 70oc 90oC 110o and 170o.The bending of about 70o and 110o is mainly caused by the middle fault of nanowires and the appearance of twins. The bending of about 90 o comes from local non-crystallization. In chapter 4th, the microstructure of indium phosphide nanowires was studied by transmission electron microscopy. It is found that the prepared indium phosphide nanowires have face-centered cubic structure and twinning defects. The twin defect density increases with the increase of nanowire diameter, which is mainly due to the difference in the size of the catalyst head of the nanowires with different diameters, resulting in the different degree of supersaturation of indium in the catalyst.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304;TB383.1

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