Mn掺杂ZnO薄膜的结构及光学性能研究

通过脉冲激光沉积(PLD)法在SiO₂基片上制备了不同含量的Mn掺杂ZnO薄膜.X射线衍射、X射线能谱、原子力显微镜与紫外-可见分光光度计测试结果表明：少量的Mn离子的掺杂并没有改变薄膜的结构，薄膜具有(103)面的择优取向；PLD法制备的ZnO薄膜的成分与靶材基本一致，实现了薄膜的同组分沉积；薄膜表面比较平坦，起伏度小于80nm，颗粒尺寸主要集中在25nm附近；但是Mn离子的掺杂改变了ZnO薄膜的禁带宽度，随Mn掺杂含量的增加，ZnO薄膜的禁带宽度增加；当薄膜中Mn含量从6%增加到 关键词： PLD ZnO薄膜 Mn掺杂 吸收谱     

Na-Mg共掺杂ZnO薄膜的结构和光学性质

利用溶胶-凝胶法,在普通载玻片上使用旋转涂膜技术制备了具有c轴择优取向生长的Na-Mg共掺杂的ZnO薄膜。用XRD、SEM、光致发光(PL)及透射光谱对薄膜样品进行了表征。结果表明:Na-Mg共掺杂有利于ZnO薄膜的c轴择优取向生长,并且随着Na+掺杂浓度的增加,晶粒尺寸先增大后减小;通过比较不同掺杂浓度ZnO薄膜的PL谱,推测发光峰值位于380nm的紫外发射与ZnO的自由激子复合有关;发现掺入Mg的确能使ZnO禁带宽度增大,掺杂组分为Na0.04Mg0.2Zn0.76O时,其PL谱只有一个很强的紫光发射峰,其近带边紫外光发射强度较未掺杂的ZnO增强了近10倍,极大地提高了薄膜紫外发光性能;并且随Na+浓度增加薄膜透光性减弱。     

生长温度对磁控溅射ZnO薄膜的结晶特性和光学性能的影响

采用反应射频磁控溅射方法，在Si (100) 基片上制备了具有高c轴择优取向的ZnO薄膜.利用 原子力显微镜、透射电子显微镜、X射线衍射分析、拉曼光谱等表征技术，研究了沉积温度 对ZnO薄膜的表面形貌、晶粒尺度、应力状态等结晶性能的影响；通过沉积温度对透射光谱 和光致荧光光谱的影响，探讨了ZnO薄膜的结晶特性与光学性能之间的关系.研究结果显示， 在室温至500℃的范围内，ZnO薄膜的晶粒尺寸随沉积温度的增加而增加，在沉积温度为500 ℃时达到最大；当沉积温度为750℃时，ZnO薄膜的晶粒尺度有所减小；在室温至750℃的范 围内，薄膜中ZnO晶粒与Si基体之间均存在着相对固定的外延关系；在沉积温度低于500℃时 ，制备的ZnO薄膜处于压应变状态，而750℃时沉积的薄膜表现为张应变状态.沉积温度的不 同导致ZnO薄膜的折射率、消光系数、光学禁带宽度以及光致荧光特性的变化，沉积温度对 紫外光致荧光特性起着决定性的作用.此外，探讨了影响薄膜近紫外光致荧光发射的可能因 素. 关键词： ZnO薄膜 表面形貌 微观结构 光学常数     

ZnO：Sb薄膜的光致发光及拉曼特性研究

利用射频磁控溅射法（MS．RF）在玻璃基片上制备了不同掺杂浓度的ZnO：Sb薄膜．借助X射线衍射仪（XRD）、透射光谱、光致发光谱（PL）和拉曼散射光谱（Raman）等手段研究了Sb掺杂浓度对ZnO薄膜的微结构、光致发光和拉曼特性的影响．结果表明：所有样品均呈现ZnO六角纤锌矿结构且具有高度C轴择优取向;在Sb掺杂ZnO薄膜的拉曼光谱中观察到位于532cm^-1的振动模式,结合XRD分析认为此峰归因于Sb替代Zn位且与0成键的局域振动模式（LVMSb--O）;光致发光谱测试发现,仅在ZnO：Sb薄膜中观察到位于3．11eV附近的紫光发射峰,结合拉曼光谱分析认为此峰与XbZn-O复合体缺陷相关．     

溶胶-凝胶法制备Zn1-xMgxO薄膜及其发光性质

采用溶胶-凝胶工艺在玻璃衬底上制备了Zn1-xMgxO(x=0.1,0.2,0.3,0.4,0.5,0.6,0.7)薄膜。X射线衍射(XRD)谱测试结果发现:在0.10.3时出现MgO立方相。薄膜光致发光谱研究表明紫外发光峰随Mg含量的增加向短波方向移动,且随着退火温度的升高发生明显蓝移,禁带宽度增大。但是退火温度为590℃的样品较560℃样品的发光峰出现红移。     

Mn掺杂对ZnO薄膜结构及发光性能的影响

利用脉冲激光沉积的方法在Si衬底上生长出了c轴高度取向的Mn掺杂ZnO薄膜.X射线衍射表明所有样品都具有纤锌矿结构,没有发现其它相,随着掺杂量的增加,c轴晶格常数增大.原子力显微镜结果显示:Mn的掺杂引起了ZnO薄膜表面粗糙度的变化.由光致发光谱发现,在387 nm附近出现了由于近带边自由激子复合引起的紫外峰,还有以4...     

Fe、Ni共掺杂ZnO基稀磁半导体光学性能与铁磁性研究

采用水热法成功制备了不同掺杂浓度的Zn1-2x Fe x Ni x O(x=0,0.025,0.05,0.1)稀磁半导体材料,利用X射线衍射(XRD)、透射电子显微镜(TEM)和X射线能量色散分析仪(XEDS)对样品进行表征,并结合拉曼(Raman)光谱、光致发光光谱(PL)和振动样品磁强计(VSM)研究样品的光学性能和磁学性能。结果表明,水热法制备的样品具有结晶性良好的纤锌矿结构,没有杂峰出现,形貌为纳米棒状结构,分散性良好。Fe2+、Ni2+是以替代的形式进入ZnO晶格中,Fe和Ni的掺杂使得晶体中的缺陷和应力增加,拉曼光谱峰位发生红移,光致发光光谱发生猝灭现象。另外,共掺杂样品在室温条件下存在明显的铁磁性,饱和磁化强度随着掺杂量的增加而增强。     

钼掺杂氧化锌薄膜的结构、光学和表面等离子体特性研究

室温下,通过直流磁控反应溅射在石英衬底上制备一系列钼掺杂氧化锌薄膜。分别采用X射线衍射(XRD)、原子力显微镜(AFM)、分光光度计及拉曼光谱仪研究了钼掺杂浓度对氧化锌薄膜结构、表面形貌、光学性能和表面等离子体特性的影响。XRD测试结果表明,零掺杂氧化锌薄膜结晶良好,呈c轴择优取向,掺杂后薄膜缺陷增多,结晶质量下降,当掺杂浓度达到3.93 Wt%时,薄膜由c轴择优取向的晶态转变为非晶态。AFM测试结果表明非晶态掺钼氧化锌薄膜表面光滑,粗糙度最低可达489 pm。透射光谱表明所有薄膜样品在可见光范围(400～760 nm)平均透过率均达到80%,禁带宽度随着掺杂浓度的提高从3.28 eV单调增加至3.60 eV。吸收光谱表明氧化锌薄膜表面等离子体共振吸收峰随钼掺杂量的增大发生蓝移,而拉曼光谱表明Mo重掺杂时ZnO薄膜表面拉曼散射信号强度显著降低。通过Mo掺杂获得非晶态氧化锌薄膜,拓宽了氧化锌薄膜材料的应用领域,同时研究了Mo掺杂浓度对氧化锌薄膜表面等离子体的调控作用,这对制备氧化锌基光子器件具有重要参考价值。     

膜厚对射频磁控溅射法制备的SnS薄膜结构和光学性质的影响

利用射频磁控溅射法在玻璃衬底上制备SnS薄膜,用X射线衍射(XRD)、能谱仪(EDS)、原子力显微镜(AFM)、场发射扫描电镜(FE-SEM)和紫外-可见-近红外分光光度计(UV-Vis-NIR)分别对所制备的薄膜晶体结构、组分、表面形貌、厚度、反射率和透过率进行表征分析。研究结果表明:薄膜厚度的增加有利于改善薄膜的结晶质量和组分配比,晶粒尺寸和颗粒尺寸随着厚度的增加而变大。样品的折射率在1 500~2 500 nm波长范围内随着薄膜厚度的增加而增大。样品在可见光区域吸收强烈,吸收系数达10⁵ cm^-1量级。禁带宽度在薄膜厚度增加到1 042 nm时为1.57 eV,接近于太阳电池材料的的最佳光学带隙(1.5 eV)。     

火焰喷雾法合成ZnO和MgxZn1-xO纳米颗粒的光学性能研究

利用火焰喷雾法成功制备了纳米级的ZnO和Mgxzn1-xO颗粒.通过对样品的X射线衍射谱和场发射扫描电子显微镜照片分析,发现制备的颗粒大小较为均匀,直径在20 nm左右;镁元素的掺入引起晶格常数变小.通过透射光谱和光致发光谱的测量,发现MgxZn1-xO颗粒的禁带宽度远大于ZnO颗粒的禁带宽度,同时对两组样品的紫外发光和可见发光的强度变化和发光机理进行了探讨.     

Strong ultraviolet emission from zinc oxide thin films prepared by electrophoretic deposition

In this paper, we report a simple and efficient method to prepare high-quality nanocrystalline ZnO films by electrophoretic deposition. Absorption spectrum and transmission electron microscope image indicated that the average size of ZnO nanoparticles is about 9.5 nm. A strong ultraviolet emission peak at 384 nm is observed and the deep-level emission band is barely observed at room temperature. X-ray diffraction pattern revealed that the ZnO film has a polycrystalline hexagonal wurtzite structure. The Raman spectrum showed a typical resonant multi-phonon process within the ZnO film. The frequency shift of 1 LO phonon was about 583 cm⁻¹.     

Ultraviolet emission of ZnO film prepared by electrophoretic deposition

We deposited high quality ZnO film by electrophoretic deposition (EPD) using high quality ZnO powder prepared by solid-state pyrolytic reaction. X-ray photoelectron spectroscopy (XPS) and the infrared (IR) absorption spectrum clearly indicate that the ZnO phase powder has been prepared. Transmission electron microscope (TEM) imaging and x-ray diffraction (XRD) show that the average grain size of the powder is about 20nm. XRD and selected-area electron diffraction (SAED) reveal that the ZnO film has a polycrystalline hexagonal wurtzite structure. Only a strong ultraviolet emission peak at 390nm can be observed at room temperature.     

低温电化学沉积ZnO薄膜及光学性质

利用阴极还原沉积原理,在水浴65℃的Zn(NO3)2水溶液中,以金属锌片为衬底电沉积制备了ZnO薄膜。采用拉曼光谱和低温光致发光谱(LTPL)对ZnO膜的光学性质进行了表征。实验表明,较小电沉积过电位制备的样品没有明显的与富锌缺氧有关的580cm-1附近的拉曼峰,呈现373nm的紫外光致发光峰,说明较小的电沉积过电位有利于高晶体质量的ZnO膜生长。     

Fabrication of Mg-doped ZnO thin films by laser ablation of Zn:Mg target

Mg-doped ZnO thin films were fabricated by laser ablation of Zn:Mg targets consisting of Mg metallic strips and Zn disk in oxygen atmosphere with a goal to facilitate convenient control of Mg contents in the films. The characteristics of the deposited films were examined by analyzing their photoluminescence (PL), X-ray diffraction and X-ray photoelectron spectroscopy (XPS) spectra. Mg contents as analyzed by XPS indicate that the target composition is fairly transferred to the deposited films. The wurtzite structure of ZnO was conserved even for the highly doped ZnO films and there was no Mg- or MgO-related XRD peaks. With increase in the Mg content, the bandgap and PL peak energy shifted to blue and the Stokes shift became larger.     

高质量ZnO及BeZnO薄膜的发光性质

用分子束外延设备插入缓冲层在c面蓝宝石上生长得到高质量ZnO和BeZnO薄膜。XRD测试显示薄膜具有六方结构和c轴取向,并具有良好的晶体质量,其中ZnO薄膜的半高宽仅为108 arcsec,Be_xZn_1-xO薄膜的半高宽小于600 arcsec。对ZnO和BeZnO薄膜的拉曼光谱进行对比研究发现,随着Be元素的掺入,A₁(LO)、A₁(2LO)声子模频率往大波数方向移动,并且首次发现了与Be元素掺杂有关的局域振动模。利用变温光致发光光谱研究了薄膜的发光性质,结果显示ZnO薄膜室温光致发光只出现一个紫外发发光峰(378 nm),而低温光谱(80 K)则出现了很强的自由激子发光峰。随着温度的升高,束缚激子发光逐渐湮灭向自由激子发光转变,并且峰值位置红移。相对于ZnO薄膜,BeZnO薄膜的紫外发光主峰位置蓝移,并且由于Be元素的掺入导致薄膜晶体质量下降,在低温(80 K)光致发光光谱中没有出现强的自由激子发光峰。另外,在低温光致发光及拉曼光谱中,主峰位置在100~200 K之间有局部最大值,推测为由于合金晶格热膨胀系数失配而引起的应力效应。     

改进的SILAR法制备ZnO薄膜及其表征

采用一种改进的液相成膜技术——连续离子层吸附与反应(SILAR)法, 用锌氨络离子\[Zn(NH3)4\]2+ 溶液作为独立的前驱体溶液, 以载玻片为衬底, 在(125±5) ℃的温度下沉积出致密、 透明的ZnO薄膜。 分别用冷场发射型扫描电镜(FESEM)和X射线衍射(XRD)分析了薄膜样品的表面形貌和结晶状态, 用紫外可见分光光度计(UV-Vis spectroscopy)研究了薄膜样品的发光性能。 结果表明: 获得样品为六角纤锌矿结构的多晶薄膜材料沿\[002\]方向择优生长; 样品表面均匀、 致密, 厚度约为550 nm;在可见光波段具有高的透射率(＞80％)。 A modified solution method,successive ionic layer adsorption and reaction(SILAR),was applied to prepare transparent zinc oxide(ZnO) film on glass substrate at (125±5) ℃ in mixed ion precursor solution. The surface morphology and crystallizations of films were analyzed by field emission scanning microscopy(FESEM) and X ray diffraction(XRD), respectively. The optical properties of the films were studied by ultraviolet visible(UV Vis)spectroscopy. The results show that the obtained samples are polycrystalline films of hexagonal wurtzite structure,with the preference of [002\] orientation. The as deposited films exhibit uniform and compact surface morphology, with the film thickness of 550 nm, and have high transmittance in the visible band(＞80％).     

Influence of Concentration of Vanadium in Zinc Oxide on Structural and Optical Properties with Lower Concentration

ZnO films doped with different vanadium concentrations are deposited onto glass substrates by dc reactive magnetron sputtering using a zinc target doped with vanadium. The vanadium concentrations are examined by energy dispersive spectroscopy （EDS） and the charge state of vanadium in ZnO thin films is characterized by x-ray photoelectron spectroscopy. The results of x-ray diffraction （XRD） show that all the films have a wurtzite structure and grow mainly in the c-axis orientation. The grain size and residual stress in the deposited films are estimated by fitting the XRD results. The optical properties of the films are studied by measuring the transmittance. The optical constants （refractive index and extinction coefficient） and the film thickness are obtained by fitting the transmittance. All the results are discussed in relation with the doping of the vanadium.     

Comparative research on the optical properties of three surface patterning ZnO ordered arrays

We fabricate three surface patterning zinc oxide(ZnO) ordered arrays on glass substrates by using nanosphere lithography technique and dc magnetron sputtering technique. The crescent, tube and honeycomb surface morphologies of the samples are observed by scanning electron microscopy. The transmittance, fluorescence and confocal Raman spectra of the sample are measured. Obviously, when the angle between the plume and the substrate is 90?, the honeycomb arrays have a better transmission. Additionally, the PL intensity of honeycomb arrays is superior. With the increasing of the angle between the substrate and the sputtering plume, the fluorescence peak shows blue shift. The Raman peak located at438 cm-1belongs to ZnO E2(high) mode, which corresponds to the characteristic band of the hexagonal wurtzite phase.The tube arrays have the best Raman spectrum intensity.     

MgB2超导薄膜的变温拉曼光谱研究

MgB₂作为迄今为止超导转变温度最高的合金超导体,由于其具有结构简单、相干长度长、晶界间不存在弱连接、上临界场很高、电-声散射时间短等特点,MgB₂超导薄膜在电子学领域有着广阔的的应用前景。拉曼光谱是研究电-声子相互作用和超导能带的一种有效方法,且已广泛用于分析MgB₂材料的电子、声子特征以及超导体能带结构,研究表明,样品质量、晶粒尺寸以及测试条件对MgB₂拉曼峰的峰位和峰形影响很大,其中拉曼光谱随温度的变化也是一个研究重点,但目前关于MgB₂变温拉曼光谱的研究,测试的温度范围相对较小,局限在83 K到室温区域或是转变温度附近。研究了大范围温度区间内MgB₂薄膜的拉曼光谱变化,采用混合物理化学沉积法在(0001)SiC衬底上制备了MgB₂多晶薄膜,薄膜的晶粒尺寸约为300 nm,超导转变温度为39.3 K,对其在10～293 K之间的拉曼光谱进行了测试,测量的波数范围为20～1 200 cm-1。变温拉曼光谱的测试结果显示,在高频620 cm-1附近以及低频80和110 cm-1附近存在MgB₂的拉曼峰。经分析,低频区域出现的两个拉曼峰的频率与超导能隙宽度相对应,表明MgB₂的双能隙特性。考虑到MgB₂中四种声子模式的拉曼活性,高频620 cm-1附近的拉曼峰应是由E_2g振动模所贡献的,且随着测试温度的降低,该拉曼峰的峰位未发生明显的偏移,但半高宽显著变小,从293 K时的380.7 cm-1减小到10 K时的155 .7 cm-1,分析表明E_2g声子与电子系统的非线性耦合所引起的非简谐效应可能是拉曼峰半高宽线性变小的主要原因。     

Modulation of electrical and optical properties of gallium-doped ZnO films by radio frequency magnetron sputtering

Ga-doped ZnO(GZO) films are prepared on amorphous glass substrates at room temperature by radio frequency magnetron sputtering.The results reveal that the gallium doping efficiency,which will have an important influence on the electrical and optical properties of the film,can be governed greatly by the deposition pressure and film thickness.The position shifts of the ZnO(002) peaks in X-ray diffraction(XRD) measurements and the varied Hall mobility and carrier concentration confirms this result.The low Hall mobility is attributed to the grain boundary barrier scattering.The estimated height of barrier decreases with the increase of carrier concentration,and the trapping state density is nearly constant.According to defect formation energies and relevant chemical reactions,the photoluminescence(PL) peaks at 2.46 eV and 3.07 eV are attributed to oxygen vacancies and zinc vacancies,respectively.The substitution of more Ga atoms for Zn vacancies with the increase in film thickness is also confirmed by the PL spectrum.The obvious blueshift of the optical bandgap with an increase of carrier concentration is explained well by the Burstein-Moss(BM) effect.The bandgap difference between 3.18 eV and 3.37 eV,about 0.2 eV,is attributed to the metal-semiconductor transition.