摘要:ZnO是一种宽禁带的直接带隙氧化物半导体材料,它具有低介电常数、大光电耦合系数、高化学稳定性、高的激子结合能以及优良的光学、电学及压电特性等,因此在许多方面有着潜在的使用价值,可广泛的应用于太阳能电池、压电薄膜、光电器件、气敏器件和紫外探测器等方面。ZnO作为一种典型的半导体材料,其价格低廉,来源丰富,稳定性好。近年来,基于ZnO稀磁半导体在自旋电子器件方面的潜在应用价值,推动了国内外材料研究工作者的广泛研究,其中Mn掺杂ZnO基稀磁半导体的研究尤其引起了较多的关注,但实验对其铁磁性的来源还存在诸多争议。本课题采用超声喷雾热解法(USP)制备Mn掺杂ZnO稀磁薄膜样品,并采用X射线衍射(XRD)、X射线光电子能谱(XPS)和超导量子干涉(SQUID)等测试手段研究其结构和磁性能,进而讨论其磁性来源。结果发现Mn掺杂ZnO薄膜中室温铁磁性与空穴载流子存在强烈的依赖关系,这与空穴为媒介的束缚磁极化子的理论预测是一致。37715
毕业论文关键词:Mn掺杂ZnO薄膜;超声喷雾热解法;稀磁半导体
Preparation of Mn - doped dilute magnetic ZnO films
Abstract:ZnO is a direct band gap oxide semiconductor material with a wide band gap,a low dielectric constant, large exciton coupling coefficient, high chemical stability, high binding energy and excellent optical, electrical and piezoelectric properties etc., therefore it has a potential application value in many aspects such as solar cell, piezoelectric films, photoelectric devices, gas sensor and UV detector etc..As a typical semiconductor, ZnO is a cheap, abundant source and has good stability. In recent years, transition-mental doped ZnO materials have promoted material researchers at home and aboard to do the extensive researches due to their potential application in spintronics, and the study of Mn- doped ZnO based diluted magnetic semiconductors (DMSs) has especially attracted many interestings, however, there are still many disputes on the origin of ferromagnetism during the experiments. In this paper, we prepared the Mn-doped ZnO diluted magnetic thin films by ultrasonic spray pyrolysis(USP). The structure and magnetic properties were studied by the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and superconducting quantum interference (SQUID), and then the origin of magnetism was explored. By analyzing the experimental results, it is found that the room-temperature ferromagnetism has a strong dependence on the hole carrier in Mn-doped ZnO films, which confirms the theoretical prediction on the ferromagnetism originating from the hole-mediated bound magnetic polarons.
Key words: Mn-doped ZnO films, ultrasonic spray pyrolysis (USP), diluted magnetic semiconductors (DMSs).
目录
1 绪论 6
1.1引言 6
1.2研究背景和意义 6
1.3主要研究内容 7
2 氧化锌概述 7
2.1 ZnO的晶体结构 8
2.2 ZnO的形态 9
2.3 ZnO薄膜的应用 9
2.3.1 透明导电薄膜 9
2.3.2 压敏元件 10
2.3.3 气敏元件 10
2.3.4 发光器件 10
2.3.5 紫外探测器 11
2.4 ZnO的电学特性 11
2.5 ZnO的光学特性 11
3 稀磁半导体材料及稀磁ZnO 11
3.1 稀磁半导体概述 12
3.1.1稀磁半导体的基本概念 12
3.1.2稀磁半导体的晶体结构及分类 13
3.2稀磁半导体的性质和应用 13 Mn掺杂稀磁性ZnO薄膜的制备:http://www.youerw.com/cailiao/lunwen_36551.html