Ce掺杂GaN纳米结构的制备及物性研究

发布时间：2018-05-14 01:38

  本文选题：GaN纳米线 + 稀土元素　； 参考：《新疆大学》2015年硕士论文

【摘要】：GaN是一种重要的宽带隙蓝光半导体材料,其低维纳米结构在纳米光电子器件构造中有广泛的应用前景。通过掺杂来调控GaN纳米材料的物性,具有重要的科学意义和技术价值。本论文对Ce掺杂GaN纳米线的生长和物性进行了研究,获得了以下主要结果:一、采用化学气相沉积(CVD)法,分别以Ga2O3和CeO2、金属Ga和CeCl3为反应源,高温NH3气氛下,以Au为催化剂制备出Ce掺杂的GaN纳米线,对产物进行了X射线衍射(XRD)、扫描电子显微术(SEM)、透射电子显微术(TEM)、选区电子衍射(SAED)、能量色散谱(EDS)、Raman散射和光致发光谱(PL)测试表征。结果显示,以Ga2O3和CeO2为源所得产物是六方晶系纤锌矿型GaN单晶纳米线,形貌均匀,结晶性良好,PL谱表明随着预掺杂浓度的增加,产物的近带边发射峰轻微地红移;以金属Ga和CeCl3为源所得产物同样是六方晶系纤锌矿型GaN单晶纳米线,但形貌均匀性降低,PL谱表明随着预掺杂浓度的增加,GaN的带边发射峰红移,峰强度减弱,且在396.9nm位置处产生一个较弱的发射带。二、采用固态烧结扩散法,通过两步合成Ce掺杂的GaN纳米线。第一步:利用CVD制备纯的GaN纳米线,第二步:使用第一步获得的纯GaN纳米线通过固态烧结扩散法制备Ce掺杂的GaN纳米线。对产物进行了XRD、SEM、TEM、SAED、EDS、XPS和PL测试表征。结果显示,所得产物是六方晶系纤锌矿型GaN单晶纳米线,结晶性良好,长时间的固态烧结能够促使更多的Ce元素扩散到GaN晶格中,纳米线表面出现非晶层。随着固态烧结扩散时间的延长,Ce元素在纳米线中实现了均匀分布。PL谱表明Ce掺杂GaN纳米线的带边发射峰出现了明显的红移。以上工作,以不同的实验方法实现了稀土元素Ce掺杂GaN纳米线的生长,对材料的形貌、结构和光学性质进行了研究,所得结果未见到文献报道,对GaN纳米线掺杂改性的研究将有积极的参考借鉴价值。
[Abstract]:GaN is an important wide band gap blue semiconductor material, and its low-dimensional nanostructures have a wide application prospect in the fabrication of nano-optoelectronic devices. It is of great scientific significance and technical value to regulate the physical properties of GaN nanomaterials by doping. In this paper, the growth and physical properties of ce doped GaN nanowires are studied. The main results are as follows: firstly, Ga2O3 and CEO _ 2, Ga and CeCl3 are used as reaction sources, respectively, in high temperature NH3 atmosphere. Ce doped GaN nanowires were prepared using au as catalyst. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAEDN), energy dispersion spectroscopy (EDS) and photoluminescence spectroscopy (PL). The results show that the products obtained from Ga2O3 and CeO2 are hexagonal wurtzite single crystal nanowires with uniform morphology and good crystallinity. The near band emission peaks shift slightly with the increase of predoping concentration. The products obtained from Ga and CeCl3 are also hexagonal wurtzite GaN single crystal nanowires. However, the decrease of morphology uniformity and PL spectra show that the peak intensity decreases with the increase of pre-doping concentration in the band edge emission peak of gan. A weaker emission band is generated at the 396.9nm position. Second, ce doped GaN nanowires were synthesized by solid sintering diffusion method. In the first step, pure GaN nanowires were prepared by CVD. In the second step, ce doped GaN nanowires were prepared by solid-state sintering diffusion method using the pure GaN nanowires obtained in the first step. The products were characterized by XPS and PL. The results show that the product is hexagonal wurtzite type GaN single crystal nanowires with good crystallinity. Long time solid sintering can promote the diffusion of more ce elements into the GaN lattice and the amorphous layer appears on the surface of the nanowires. The uniform distribution of ce in nanowires with the increase of the diffusion time of solid sintering shows that the emission peaks of ce doped GaN nanowires exhibit a red shift. The growth of rare earth element ce doped GaN nanowires has been achieved by different experimental methods. The morphology, structure and optical properties of the materials have been studied. The results have not been reported in the literature. The study on the doping modification of GaN nanowires will have positive reference value.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ133.51;TB383.1

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