退火温度对射频磁控溅射法生长的Mg0.16Zn0.84O薄膜性质的影响

采用射频磁控溅射的方法在硅衬底上生长出高质量的Mg0.16Zn0.84O薄膜.用X射线(XRD)、原子力显微镜(AFM)分别研究了在200、400、600和800℃下空气中退火2h的Mg0.16Zn0 84O薄膜的结构、表面形貌.结果表明,Mg0.16Zn0.84O薄膜是六角纤锌矿结构,具有沿与衬底垂直的C轴的择优取向;随着样品退火温度的升高,(002)衍射峰强度明显增强,衍射峰半高宽(FWHM)由0.86°单调地降低到0.40°,晶粒大小明显增大,最大的高达400nm以上.用TV1900型双光束紫外可见分光光度计测量了淀积在蓝宝石衬底上的Mg0.16Zn0.84O薄膜室温的透射谱,得到可见光区的平均透过率约为95%,进而估算出Mg0.16Zn0.84O薄膜的带隙宽度约为3.58eV.     

衬底温度对Mg0.1Zn0.9O薄膜结构及光学性能的影响

利用射频磁控溅射技术在不同温度的(100)Si和玻璃衬底上成功地制备了c轴择优取向的Mg0.1Zn0.9O薄膜.通过X射线衍射(XRD)、场发射扫描电镜(FESEM)、紫外可见光分光光度计和光致发光谱研究了衬底温度对Mg0.1Zn0.9O薄膜结构、表面形貌和光学性能的影响,结果表明,在衬底温度为400℃时生长的Mg0.1Zn0.9O薄膜具有很好的c轴取向和较好的光学性能.用激发波长为300nm的氙灯作为激发光源得到不同衬底温度下Mg0.1Zn0.9O薄膜的室温PL谱.分析表明,紫外发光峰与薄膜的结晶质量密切相关,蓝光发射与氧空位有关.简单探讨了衬底温度影响紫外光致发光峰红移和蓝移的可能机理.     

Zn0.85Co0.15O薄膜的制备及其结构分析

用电子束蒸镀方法在(100)单晶Si衬底上,生长Zn0.85Co0.15O薄膜,并研究了衬底温度对薄膜质量的影响,结果表明当衬底温度为400℃时,外延膜取向性最好,且其(002)衍射峰半高宽最窄(为0.4834°)。     

衬底温度对低功率直流磁控溅射ZnO薄膜特性的影响

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.     

掺Er-Al2O3薄膜发光特性的研究

通过离子束辅助沉积(IBAD)在热氧化SiO2上沉积Al2O3薄膜,在120keV下注入5×10115cm-2Er离子,Ar气氛下773～1273K退火1h.低温下测试PL谱线,随退火温度升高,发光强度上升.973K退火下发光强度特别低,并观察到Si衬底的1140nm峰.光透射谱表明几乎在所有的测试范围内尤其在1530nm处973K退火样品的透射谱强度最强,波导损耗最低.1530nm发光强度随退火温度的变化跟发光强度的变化相反.说明Er离子在514.5nm泵谱吸收界面σ跟Al2O3的光吸收损耗有一定关系.     

Al、N共掺Zn1-xMgxO薄膜的制备与性能研究

采用直流反应磁控溅射方法,由氨气和氧气的混合气体在玻璃和单晶硅衬底上制备Al、N共掺Zn1-xMgxO薄膜.采用XRD、FE-SEM、Hall实验、UV-VIS透射谱以及EDS等方法对共掺Zn1-xMgxO薄膜的结晶性能、电学和光学性能进行研究.结果表明薄膜有明显的C轴择优取向,玻璃衬底上制备的p-Zn0.9Mg0.1O薄膜的电阻率为8.28 Ω穋m,空穴浓度和迁移率分别为1.09×1019 cm-3和0.069 cm2/V穝.并且掺Mg的ZnO薄膜透射光谱表现出明显的蓝移.p-Zn0.9Mg0.1O/n-Si异质结的I-V特性曲线表现出明显的整流特性,可以确定制备的Al、N共掺Zn0.9Mg0.1O薄膜的导电类型是p型的.     

退火温度对磁控溅射SiC薄膜结构和光学性能的影响

首先采用射频磁控溅射法在单晶Si(100)衬底上沉积制备了SiC薄膜,然后将所制备的薄膜试样分别在600,800和1 000℃氩气氛中退火120 min;采用X射线衍射仪和红外吸收光谱仪分析了薄膜的结构随退火温度的变化,采用荧光分光分度计研究了薄膜的发光性能随退火温度的变化。结果表明:室温制备的SiC薄膜为非晶态,经600℃退火后薄膜结晶,且随着退火温度的升高,薄膜的结晶程度越来越好,并且部分SiC结构发生了由α-SiC到β-SiC的转变;所制备的SiC薄膜在384和408 nm处有两个发光峰,且两峰的强度均随退火温度的升高逐渐变强,其中384nm处的峰源自于SiC的发光,408 nm处的峰源自于碳簇的发光。     

[101]取向Li掺杂ZnO薄膜光学性能的研究

采用射频磁控溅射法在玻璃衬底上制备了[101]取向的Li:ZnO薄膜, 研究了该薄膜的光学性能随热处理温度变化的规律. 结果表明, 399nm的发光峰是由Li的杂质能级引起; 与[002]取向的薄膜相比, 未经热处理的[101]薄膜其光学带隙大, 且出现了380nm附近的带边发射(NBE) 峰; 在560～580℃热处理下, 其晶胞变小、光学带隙变窄、360nm 左右的带间发光峰红移; 当热处理温度升至610℃时, 薄膜中再次出现380nm的NBE峰.     

O2气流量对MOCVD法生长ZnO薄膜性质的影响

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.     

不同衬底温度下生长的Bi1.5Zn1.0Nb1.5O7.0薄膜的XPS研究

采用固相反应法合成具有焦绿石立方结构的Bi1.5Zn1.0Nb1.5 O7(BZN)陶瓷靶材,采用脉冲激光沉积法在Pt/TiO2/SiO2/Si(100)基片制备立方BZN薄膜,衬底温度在500～ 700℃范围内变化.X射线衍射测量结果表明:当在500℃沉积BZN薄膜时,薄膜呈现出无定形态结构.随着衬底温度增加到550℃,薄膜开始晶化,并且显示出立方焦绿石结构.X射线光电子能谱也被用来研究BZN薄膜的结构状态和元素价态.测试得到的全谱表明:在BZN薄膜中,除了用于定标的C元素之外,只有Bi、Zn、Nb、O元素的特征峰,此外有Ti2p特征峰出现,可能来自底电极的TiO2缓冲层.各元素的窄谱扫描表明:Bi,Zn,Nb,O四种元素的化学价态分别是+3,+2,+5,-2.BZN薄膜在550℃结晶,随着衬底温度升高到600℃,金属阳离子的结合能的峰位向高能方向移动,然而O1s的特征峰位也向高能方向移动,这归因于薄膜中存在的氧空位.     

Effect of the oxygen partial pressure on the microstructure and optical properties of ZnO:Cu films

Cu-doped zinc oxide (ZnO:Cu) films were deposited on Si substrates using radio frequency reactive magnetron sputtering at different oxygen partial pressures. The effect of oxygen partial pressure on the microstructures and optical properties of ZnO:Cu thin films were systematically investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and fluorescence spectrophotometer. The results indicated that the grain orientation of the films was promoted by appropriate oxygen partial pressures. And with increasing oxygen partial pressure, the compressive stress of the films increased first and then decreased. The photoluminescence (PL) of the samples were measured at room temperature. A violet peak, two blue peaks and a green peak were observed from the PL spectra of the four samples. The origin of these emissions was discussed and the mechanism of violet emission of ZnO:Cu thin films were suggested.     

氧氩比对磁控溅射ZnO薄膜结构及光致发光性能的影响

采用射频反应磁控溅射法以不同的氧氩比在玻璃衬底上制备了ZnO薄膜,并对薄膜进行了退火处理;利用X射线衍射仪（XRD）和原子力显微镜（AFM）分别对薄膜的物相组成和表面形貌进行了分析,利用荧光分光光度计对ZnO薄膜的室温光致发光（PL）谱进行了测试。结果表明：当氧氩气体积比为7∶5时,所制备的ZnO薄膜晶粒细小均匀,薄膜结晶质量最好;ZnO薄膜具有紫光、蓝光和绿光三个发光峰,随着氧氩比的增加,蓝光的发射强度增强,而紫光和绿光的发射强度先增强后减弱,当氧氩气体积比为7∶5时紫光和绿光的发射强度最强。     

ZnxMg1-xS多晶薄膜的制备及其特性研究

采用真空蒸镀技术,在普通石英玻璃衬底上成功制备出固溶体ZnxMg1-xS多晶薄膜.用X射线能量色散谱仪、原子力显微镜、X射线衍射仪、紫外-可见分光光度计等对薄膜晶体成分、表面形貌、结构和光学性质做了分析.结果表明当x＝0.9时,固溶体ZnxMg1-xS晶体形貌生长和结晶性良好,为闪锌矿结构;由于镁成分的掺入,ZnxMg1-xS薄膜的(111)峰位相对于ZnS的(111)峰位向大角度方向移动0.14°;光学吸收边相对于ZnS产生了明显的蓝移,其禁带宽度增加0.19 eV,显示了作为短波光电器件材料和紫外探测材料的应用潜力.     

Structural, Morphological and Optical Properties of ZnO Thin Films Grown on γ-LiAlO2 Substrate by Pulsed Laser Deposition

ZnO thin films were deposited on the substrates of (100) γ-LiAlO2 at 400, 550 and 700℃ using pulsed laser deposition (PLD) with the fixed oxygen pressure of 20 Pa, respectively. When the substrate temperature is 400℃, the grain size of the film is less than 1 μm observed by Leitz microscope and measured by X-ray diffraction (XRD). As the substrate temperature increases to 550℃, highly-preferred c-orientation and high-quality ZnO film can be attained.While the substrate temperature rises to 700℃, more defects appears on the surface of film and the ZnO films become polycrystalline again possibly because more Li of the substrate diffused into the ZnO film at high substrate temperature. The photoluminescence (PL) spectra of ZnO films at room temperature show the blue emission peaks centered at 430 nm. We suggest that the blue emission corresponds to the electron transition from the level of interstitial Zn to the valence band. Meanwhile, the films grown on γ-LiAlO2 (LAO) exhibit green emission centered at 540 nm, which seemed to be ascribed to excess zinc and/or oxygen vacancy in the ZnO films caused by diffusion of Li from the substrates into the films during the deposition.     

Optical and structural analysis of porous silicon coated with GZO films using rf magnetron sputtering

In the production of porous silicon (PS) to optoelectronic application one of the most significant constrains is the surface defects passivation. In the present work we investigate, gallium-doped zinc oxide (GZO) thin films deposited by rf magnetron sputtering at room temperature on PS obtained with different etching times. The X-ray diffraction (XRD), Fourier transform infrared (FTIR) and atomic force microscopy (AFM) analysis have been carried out to understand the effect of GZO films coating on PS. Further, the XRD analysis suggests the formation of a good crystalline quality of the GZO films on PS. From AFM investigation we observe that the surface roughness increases after GZO film coating. The photoluminescence (PL) measurements on PS and GZO films deposited PS shows three emission peaks at around 1.9 eV (red-band), 2.78 eV (blue-band) and 3.2 eV (UV-band). PL enhancement in the blue and ultraviolet (UV) region has been achieved after GZO films deposition, which might be originated from a contribution of the near-band-edge recombination from GZO.     

Mg-Al共掺杂ZnO薄膜的制备及其光学特性

采用溶胶-凝胶（sol—gel）旋涂法在载玻片上制备了不同A1掺杂量的Mg—Al共掺杂ZnO薄膜．在室温下利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）和光致发光（PL）谱仪等手段分析了Mg—Al共掺杂Zn0薄膜的微结构、形貌和发光特性．XRD结果表明Mg．AI＆掺杂zn0薄膜具有六角纤锌矿结构;随着Al掺杂量的增加,共掺杂薄膜呈C轴取向生长．由SEM照片可知薄膜表面形貌随Al掺杂量的增加由颗粒状结构向纳米棒状结构转变．透射光谱表明共掺杂薄膜在可见光区内的透射率大于50％,紫外吸收边发生蓝移．在室温下的PL谱表明Mg—Al共掺杂zn0薄膜的紫外发射峰向短波长方向移动：Al掺杂摩尔分数为1％和3％的Mg—Al共掺杂ZnO薄膜的可见发射峰分别为596nm的黄光和565nm的绿光．黄光主要与氧间隙有关,而绿光主要与氧空位有关．     

Structural and optical properties of ZnO films grown on the AAO templates

Structural and optical properties of ZnO films grown on Al substrate and anodic alumina oxide (AAO) templates by rf magnetron reactive sputtering deposition were investigated using X-ray diffraction (XRD), atomic-force microscope (AFM) and photoluminescence (PL). We found that ZnO thin films on Al substrate show good C-axis orientation, while the orientation of ZnO film on AAO templates is disordered, this due to the fact that the crystalline of ZnO is greatly influenced by surface morphology of substrates. PL measurements show a blue band in the wavelength range of 400–500 nm caused by the interstitial Zn in the ZnO films. The intensity of emission peak of ZnO films deposited on AAO templates increases compared with that on the Al substrate. Combining electrical resistivity and carrier concentration measurements, we found that that the blue emission intensity is consistent with the concentration for the interstitial zinc in the ZnO films.     

Physical and electronic properties of ZnO:Al/porous silicon

UV, violet and blue-green photoluminescence has been achieved at room temperature (RT) from ZnO:Al (AZO) films deposited by radio frequency (rf) co-sputtering. As the ZnO target power increases from 100 W, the violet luminescence vanishes and the blue and green-blue luminescences appear. The most intense UV and blue-green luminescence is obtained for the films deposited at higher sputtering powers depending upon the stoichiometry of the films as well as the crystalline quality. The as-prepared porous silicon (PS) emission band lies in the blue-green spectral region and is blue shifted due to the AZO deposition. The current–voltage characteristics of AZO/PS heterostructures have been studied. The ideality factor is found to be 19 and the series resistance as determined from the forward characteristics is 36 MΩ.     

Growth and characterization of indium phosphide nanowires on transparent conductive ZnO:Al films

The epitaxial growth of indium phosphide nanowires (InP NWs) on transparent conductive aluminum-doped zinc oxide (ZnO:Al) thin films is proposed and demonstrated. ZnO:Al thin films were prepared on quartz substrates by radio frequency magnetron sputtering, then InP NWs were grown on them by plasma enhanced metal organic chemical vapor deposition with gold catalyst. Microstructure and optical properties of InP nanowires on ZnO:Al thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectric spectroscopy (XPS), photoluminescence and Raman spectroscopy at room temperature. SEM shows that randomly oriented and intersecting InP nanowires were grown to form a network on ZnO:Al thin films. Both wurtzite (WZ) and zincblende (ZB) structures coexist in the random orientation InP NWs on ZnO:Al thin film had been proved by XRD analysis. XPS result indicates Zn diffusion exists in the InP NWs on ZnO:Al. The photoluminescence spectra of InP nanowires with Zn diffusion present an emission at 915 nm. Zn diffusion also bring effect on Raman spectra of InP NWs, leading to more Raman-shift and larger relative intensity ratio of TO/LO.     

Influence of film thickness and annealing atmosphere on the structural, optical and luminescence properties of nanocrystalline TiO2 thin films prepared by RF magnetron sputtering

TiO₂ thin films were deposited onto quartz substrates by RF magnetron sputtering. Inorder to investigate the effect of film thickness on the structural and optical properties, films were deposited for different time durations, and post-annealed at 873 K. The influence of annealing atmosphere (air/oxygen) on the film properties was also investigated. The films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis spectroscopy and photoluminescence (PL) spectroscopy. Films deposited at different time durations are amorphous-like in nature. From XRD patterns it can be inferred that deposition for longer duration is essential for achieving crystallisation in TiO₂ thin films prepared by RF magnetron sputtering. The films exhibited good adherence to the substrate and are crack free as revealed by SEM images. Film thickness was found to increase with increase in sputtering time. The optical band gap of the films was found to decrease with increase in film thickness, which is consistant with XRD observations. Film thickness did not show any significant variation when annealed in both air and oxygen. Defect related PL emission in the visible region (blue) was observed in all the investigated films, which suggests the application of these films in optoelectronic display devices.