【作者】 刘超；

【导师】 何海平；

【作者基本信息】 浙江大学 ， 材料科学与工程， 2011， 硕士

【摘要】 硅材料作为一种神奇的材料,在微电子器件中得到广泛的应用,极大地推动了信息技术的迅速发展。随着硅电子器件有源区的特征尺寸缩小到纳米量级,人们对于研究硅纳米材料产生了极大的兴趣。其中一维硅纳米材料,由于具有优良的电学性能、光学性能以及与硅微电子工艺的兼容性,得到了极大的重视。另外,多孔硅具有室温光致发光特点的发现,引起了研究人员对于硅纳米材料发光机理以及硅基光电器件的研究兴趣。本文在此基础上研究如何大规模,低成本制备硅纳米线阵列,并研究其光学性质。通过调控制备条件,获得了发光与否可控的硅纳米线阵列。研究了其发光机理,通过将其发光与局域等离子共振相结合,获得了硅纳米线阵列的发光增强。另外,我们利用不同方法制备得到了氧化锌纳米棒阵列以及纳米线,通过将氧化锌与硅纳米线阵列相结合,我们获得了Si/ZnO核壳结构。主要工作如下：1.采用金属辅助化学腐蚀的方法,通过改变反应衬底、反应溶液浓度以及反应时间等,获得了制备硅纳米线阵列的最佳反应参数。并可通过改变反应条件制备多孔硅纳米线阵列。2.通过透射电镜、扫描电镜以及荧光光谱等测试,分析硅纳米线发光的原因。并对其发光机理做了进一步分析,提出发光机理的模型。3.利用还原柠檬酸钠的方法制备金纳米颗粒,并将其局域等离子共振特性与硅纳米线的发光结合起来,使得硅纳米线阵列的发光增强达10倍。4.分别利用水热法及气相沉积法制备得到氧化锌纳米棒阵列以及纳米线。在低温下,两种样品的荧光光谱在3.34 eV附近均有一宽包。通过结合变激发强度荧光光谱以及表面钝化等分析,我们确定了其发光来源于自由电子到中性受主的复合。另外,我们利用MOCVD法在硅纳米阵列上包覆了氧化锌壳层,获得了Si/ZnO核壳结构纳米线阵列。更多还原

【Abstract】 Silicon is a wonderful material for modern electronic devices. As a fundamental material used in micro-electronics, it speeds up the development of information technology. The continuously shrinking size of silicon devices has raised interest in the properties of silicon at the nanoscale, especially one-dimensional structures such as nanowires. Silicon nanowires are under active investigation because of their unique electrical, optical properties and good compatible properties with integrated circuits. Besides, the discovery of the photoluminescence (PL) properties of porous silicon also intrigues numerous studies to understand the origin of PL, and a vast variety of applications emerged.In this thesis, we prepared wafer-scale silicon nanowire arrays with low costs; investigated the luminescence mechanism of porous silicon nanowire arrays; and obtained the enhancement luminescence of porous silicon nanowire arrays by coupling with localized surface plasmons. In addition, ZnO nanorod arrays and nanowires were grown by hydrothermal and vapor phase deposition methods, respectively. Si/ZnO core-shell nanowire array were prepared by combination of metal-assisted chemical etching and MOCVD. The main results are as follow:1. Silicon nanowire arrays were synthesized by metal-assisted chemical etching. The reaction parameters were optimized by controlling the reaction substrate, solution concentration and reaction time. We also obtained the porous silicon nanowire arrays by changing the reaction condition.2. TEM, SEM and PL characterization techniques are employed to investigate the origin and the luminescence mechanism. We proposed a schematic model to explain the luminescence mechanism.3. Au nanoparticles were synthesized by reducing sodium citrate. The luminescence intensity of nanowire arrays was enhanced ten times coupling with localized surface plasmons of Au.4. ZnO nanorod arrays and nanowires were grown by hydrothermal and vapor phase deposition methods, respectively. At low temperature, the photoluminescence (PL) spectra of both samples are dominated by a broad peak around 3.34 eV. Combined with excitation density-dependent PL spectra and surface passivation process, it is indicated that the 3.34 eV emission could be attributed to free electron-to neutral acceptor transitions. In addition, Si/ZnO core-shell nanowire array were prepared by combination of metal-assisted chemical etching and MOCVD methods.更多还原