共查询到19条相似文献,搜索用时 78 毫秒
1.
利用等离子体辅助分子束外延的方法在ZnO单晶衬底上制备了ZnO薄膜。利用X射线衍射(XRD)、同步辐射掠入射XRD和φ扫描等实验技术研究了ZnO薄膜的结构。XRD和φ扫描的结果显示同质外延的ZnO薄膜已经达到单晶水平。掠入射XRD结果表明ZnO薄膜内部不同深度处a方向的晶格弛豫是不一致的,从接近衬底界面处到薄膜的中间部分再到薄膜的表面处,a方向的晶格常数分别为0.3249,0.3258和0.3242 nm。计算得到ZnO薄膜的泊松比为0.156,同质外延的ZnO薄膜与衬底在a轴方向的晶格失配度为-0.123%。 相似文献
2.
PLD方法生长ZnO/Si异质外延薄膜的研究 总被引:3,自引:0,他引:3
用脉冲激光沉积法在Si(111)衬底上制备了ZnO薄膜。RHEED和XRD测试表明,直接沉积在Si衬底上的ZnO薄膜为多晶薄膜,且薄膜的结晶质量随衬底温度的升高而下降。相比之下,生长在一低温同质缓冲层上的ZnO薄膜则展现出规则的斑点状RHEED图像,说明它们都是外延生长的高质量ZnO薄膜。XRD与室温PL谱分析表明,外延ZnO薄膜的质量随衬底温度的升高得到明显的改善。在650℃生长的样品具有最好的结构和发光特性,其(002)衍射峰的半高宽为0.185°,UV峰的半高宽仅为86meV。 相似文献
3.
等离子体辅助反应式脉冲激光熔蚀制备AlN薄膜的低温生长 总被引:1,自引:0,他引:1
使用等离子体辅助反应式脉冲激光溅射沉积薄膜的方法在Si(111)和Si(100)基片上已经成功地低温制备出AlN多晶膜。实验表明,当脉冲能量密度DE=1.0J·cm-2,脉冲频率f=5Hz,氮气气压PN2=1.33×104Pa,基底温度tsub=200℃,放电电压V=650V,基靶距离dS-T=4cm时薄膜的生长速度等于6nm/min。AlN薄膜的折射率为2.05,和基底的取向关系分别为:AlN(110)∥Si(111)和AlN(100)∥Si(100)。 相似文献
4.
采用二乙基锌(DEZn)和氧化亚氮(N2O)作为锌源和氧源,在低温300℃,利用金属有机化学气相沉积(MOCVD)的方法在Si(100)衬底上制备了ZnO薄膜.通过优化氧锌比,ZnO薄膜为高度单一c轴方向生长.由光致发光谱和反射谱得知,ZnO薄膜的紫外发光峰位于388nm,具有很好的光透性,且其PL谱半峰宽为80meV. 相似文献
5.
在不同的衬底温度下,通过脉冲激光淀积(PLD)方法在Si衬底上生长出c轴高度取向的ZnO薄膜。ZnO薄膜的结构分别通过X射线衍射(XRD)和广延X射线吸收精细结构(EXAFS)来表征,而表面成份和化学态则通过X射线光电子能谱来研究。利用光致发光(PL)来研究样品的发光特性。XRD结果和EXAFS结果都表明了500℃时生长的ZnO薄膜的结晶性比300℃时生长的要好。EXAFS结果和XPS结果显示,300℃时生长的ZnO薄膜处于富氧状态,而500℃时生长的则处于缺氧状态。结合XRD谱、EXAFS谱、XPS谱和PL谱的结果可以看到:随着ZnO薄膜的结晶性变好,它的紫外发光增强;另一方面,随着ZnO薄膜中O的含量减少,绿光发射变强。我们的结果表明绿光发射与ZnO中氧空位(V0)有关。 相似文献
6.
采用低压MOCVD方法,在(0001)Al2O3衬底上沉积了ZnO薄膜.研究了Ⅵ族源O2气流量的变化对薄膜结构、表面形貌及光致发光特性的影响.增加O2气流量,ZnO薄膜结晶质量有所降低,半高宽从0.20°展宽至0.30°,由单一c轴取向变成无取向薄膜.同时,生成的柱状晶粒平均尺寸减少,晶粒更加均匀,均方根粗糙度减小.PL谱分析表明随O2气流量加大,带边峰明显增强,深能级峰明显减弱,ZnO薄膜光学质量提高.这些事实说明在本实验条件下,采用低压MOCVD方法生长的ZnO薄膜在光致发光特性主要依赖于Zn、O组份配比,而不是薄膜的微观结构质量. 相似文献
7.
高质量ZnO薄膜的退火性质研究 总被引:3,自引:0,他引:3
在LP-MOCVD中,我们利用Zn(C2H5)2作Zn源,CO2作氧源,在(0002)蓝宝石衬底上成功制备出皮c轴取向高度一致的ZnO薄膜,并对其进行500℃-800℃四个不同温度的退火。利用XRD、吸收谱、光致发光谱和AFM等手段研究了退火对ZnO晶体质量和光学性质的影响。退火后,(0002)ZnO的XRD衍射峰强度显著增强,c轴晶格常数变小,同时(0002)ZnOX射红衍射峰半高宽不断减小表明晶粒逐渐增大,这与AFM观察结果较一致。由透射谱拟合得到的光学带隙退火后变小,PL谱的带边发射则加强,并出现红移,蓝带发光被有效抑制,表明ZnO薄膜的质量得到提高。 相似文献
8.
衬底温度对低功率直流磁控溅射ZnO薄膜特性的影响 总被引:2,自引:0,他引:2
采用低功率直流反应磁控溅射法,在Si衬底上成功制备出了具有高c轴择优取向的ZnO薄膜,利用X射线衍射仪、荧光分光光度计研究了沉积温度对ZnO薄膜微观结构及光致发光特性的影响.结果表明,合适的衬底温度有利于提高ZnO薄膜结晶质量;在室温下测量样品的光致发光谱(PL),观察到波长位于440nm左右和485nm左右的蓝色发光峰及527nm左右微弱的绿光峰,随衬底温度升高,样品的PL谱中蓝光强度都明显增大,低功率溅射对其蓝光发射具有很重要的影响.综合分析得出440nm左右的蓝光发射应与Zni有关,485nm附近的蓝光发射是由于氧空位形成的深施主能级上电子跃迁到价带顶的结果,而527nm左右的较弱的绿光发射主要来源于导带底到氧错位缺陷能级的跃迁.生长温度主要是通过改变薄膜中缺陷种类及浓度而影响着ZnO薄膜的发光特性的. 相似文献
9.
对MOCVD生长GaN:Si薄膜进行了研究,研究表明随SiH4/TMGa流量比增大,GaN:Si单晶膜的电子浓度增大,迁移率下降,X射线双晶衍射峰半高宽增加,同时这发射强度得到了大大的提高,并报导了随SiH4/TMGa流量比增大,GaN:Si的生长速率降低的现象,研究结果还表明,预反应对GaN:Si单晶膜黄带发射影响很大,预反应的减小可以使黄带受到抑制。 相似文献
10.
采用基片加热和后期热处理的手段使ITO薄膜结晶和调整其组织结构来降低电阻的方法,已经被广泛应用于在玻璃等基体上制备ITO薄膜.但是随着不耐高温的柔性基体的广泛使用,ITO薄膜低温生长已经成为一个重要的研究课题.为此,本研究探讨室温等离子体辅助条件下,ITO薄膜沉积生长过程,以期为上述问题的解决提供理论依据.研究结果表明等离子辅助可以有效控制ITO薄膜的结晶程度和晶粒尺寸以及晶界结构,在优化条件下,在PET基体上制备出电阻率为1.1×10-3Ω·cm的ITO薄膜. 相似文献
11.
Guotong DuJinzhong Wang Xinqiang WangXiuying Jiang Shuren YangYan Ma Wei YanDingsan Gao Xiang LiuHui Cao Junying XuR.P.H. Chang 《Vacuum》2003,69(4):473-476
ZnO films were grown on C-plane sapphire substrate by plasma-assisted MOCVD. The films was characterized by XRD, photoluminescence (PL) and the optical transmission spectrum. We found tensile strain in the sample, which had been annealed many times during the growth process, while there is compressive strain in the sample, which was annealed only one time after growth. The PL spectra at room temperature for the sample annealed many times exhibited only one emitting peak at around 380 nm. However, we find Γ5 and Γ6 free exciton peaks in the sample annealed only one time after growth. At the same time, the optical transmission indicate that the maximum of the sample's transmission decreases against with the increasing of the c-axis length in ranges from 190 to 900 nm. 相似文献
12.
Diluted magnetic semiconductor epitaxial thin films of Zn1 − xMnxO have been grown on c-sapphire by the MOCVD technique. Variations of a and c lattice parameters follow Vegard's law and attest to the incorporation of substitutional Mn2+ ions. Carrier concentration (n-type) and electron mobility were studied versus temperature for different concentrations of manganese. Incorporation of manganese leads to the opening of the band gap, observed as a blue shift in energy regarding pure ZnO. 相似文献
13.
The surface treatment effects of sapphire substrate on the quality of epitaxial ZnO thin films grown by metal-organic chemical vapor deposition (MOCVD) were studied. The sapphire substrates have been investigated by means of atomic force microscopy (AFM) and X-ray diffraction rocking curves (XRCs). The results show that sapphire substrate surfaces have the best-quality by CMP with subsequent chemical etching. The surface treatment effects of sapphire substrate on the ZnO thin films were examined by X-ray diffraction (XRD), atomic force microscopy (AFM) and photoluminescence (PL) measurements. Results show that the intensity of (002) diffraction peak of ZnO thin films on sapphire substrates treated by CMP with subsequent chemical etching is strongest. FWHM of (002) diffraction peak is narrowest and the intensity of UV peak of PL spectrum is strongest, indicating surface treatment on sapphire substrate preparation may improve ZnO thin films crystal quality and photoluminescent property. 相似文献
14.
Yangfan Lu Zhizhen Ye Yujia Zeng Weizhong Xu Liping Zhu Binghui Zhao 《Optical Materials》2007,29(12):1612-1615
High quality N-doped ZnO films were grown at different RF powers on glass substrates by plasma-assisted metalorganic chemical vapor deposition. Scanning electron microscopy, X-ray diffraction and Hall analyses were carried out to investigate the effects of RF power variation on surface morphology, crystallinity and electrical properties of the ZnO films. Increasing the RF power resulted in compacter surface morphology and change of the crystallinity as well as incorporation of more N atoms. Films grown at 150 W exhibited the best p-type electrical properties. Moreover, room temperature photoluminescence spectra showed strong emission related to N acceptor. 相似文献
15.
一种新型的MOCVD(Mettalic Organism CVD)装置,既金属有机化合物CVD沉积装置。该装置具有结构简单,在低温、低压条件下能够实现化学气相沉积反应。气路系统全部采用进口零部件,保证反应气体的纯度。等离子体在反应过程中起到辅助和掺杂的作用。经实验表明该装置能够较好地完成氧化锌薄膜的研究工作,也可为进一步的研究提供必要的条件。 相似文献
16.
A. Marzouki F. Falyouni A. Lusson L. Rigutti M. Tchernycheva V. Sallet 《Materials Letters》2010,64(19):2112-272
One dimensional nitrogen-doped ZnO nanowires were deposited on C-plane sapphire using metal organic chemical vapour deposition. Nanowires have been characterized by scanning electron microscopy, transmission electron microscopy, micro-Raman scattering and micro-photoluminescence spectroscopy. The structural analysis has shown a high crystalline quality. In N-doped ZnO nanowires nitrogen incorporation was emphasized by Raman spectral analysis and reduction of nitrogen concentration along the wire, from the bottom to the top was found by local analysis. Low temperature micro-photoluminescence spectra exhibit donor-acceptor pair transitions. 相似文献
17.
M. P. Singh G. Raghavan A. K. Tyagi S. A. Shivashankar 《Bulletin of Materials Science》2002,25(2):163-168
Spectroscopic ellipsometry was used to characterize carbonaceous, crystalline aluminium oxide films grown on Si(100) by low-pressure
metal organic chemical vapour deposition, using aluminium acetylacetonate as the precursor. The presence of carbon in the
films, attributed to the use of a metalorganic precursor for the deposition of films, was identified and analysed by secondary
ion mass spectroscopy and X-ray photoelectron spectroscopy, for the elemental distribution and the chemical nature of the
carbon in the films, respectively. Ellipsometry measurements over the photon energy range 1.5–5 eV were used to derive the
pseudo-dielectric function of the aluminium oxide-containing films. Multi-layer modelling using linear regression techniques
and the effective medium approximation were carried out to extract the structural details of the specimens. The excellent
fit between the simulated and experimental optical data validates the empirical model for alumina-containing coatings grown
by MOCVD. 相似文献
18.
100 nm InN layer was grown on sapphire c-plane using a metal-organic chemical vapor deposition (MOCVD) system. Low temperature (LT) GaN layer was grown on InN layer to protect InN layer from direct exposure to hydrogen flow during high temperature (HT) GaN growth and/or abrupt decomposition. Subsequently, thick HT GaN layer (2.5 μm thick) was grown at 1000 °C on LT GaN/InN/sapphire template. Microstructure of epilayer-substrate interface was investigated by transmission electron microscopy (TEM). From the high angle annular dark field TEM image, the growth of columnar structured LT GaN and HT GaN with good crystallinity was observed. Though thickness of InN interlayer is assumed to be about 100 nm based on growth rate, it was not clearly shown in TEM image due to the InN decomposition. The lattice parameters of GaN layers were measured by XRD measurement, which shows that InN interlayer reduces the compressive strain in GaN layer. The relaxation of compressive strain in GaN layer was also confirmed by photoluminescence (PL) measurement. As shown in the PL spectra, red shift of GaN band edge peak was observed, which indicates the reduction of compressive strain in GaN epilayer. 相似文献
19.
Synthesis and characterization of BN thin films prepared by plasma MOCVD with organoboron precursors
Boron nitride (BN) films have contributed to improvement of tribological parts. For this study, we prepared films using plasma MOCVD with an organoborate precursor and investigated the mechanical properties and structure of BN films. The BN films were formed on specimens of silicon wafers and tungsten carbide (WC) substrates at low temperatures of less than 500 °C. Hardness tests were carried out to evaluate mechanical properties of BN films. The structure of BN films was investigated using XRD, Raman, and FT-IR spectra. 相似文献