反应沉积法制备c轴取向ZnO薄膜及表征

以二水合醋酸Zn为原料 ,采用反应沉积方法在非晶玻璃衬底上制备出了高度c轴取向、结晶良好的ZnO薄膜。研究了不同衬底温度和Zn源温度对ZnO薄膜性质的影响 ,探讨了不同衬底温度和Zn源温度下生长ZnO薄膜的最佳参数。本文还讨论了该方法制备ZnO薄膜的沉积机制及优化条件下样品的透光特性。     

Growth and surface topography of cadmium films

The growth of cadmium films deposited on amorphous glass substrate were studied using X-ray diffraction and transmission electron microscopy techniques. The analysis of the experimental data showed a very high preferred orientation of the crystallites with the crystallographic c-axis normal to the substrate, indicating a layer type growth with high preferred orientation of the basal planes parallel to the substrate. The films obtained at room temperature were polycrystalline in nature with large grain size. Surface features were studied using SEM, indicating a larger crystallite size for films grown on a few atomic layers of titanium on glass substrate.     

Effect of the [Al/Zn] ratio in the starting solution and deposition temperature on the physical properties of sprayed ZnO:Al thin films

Aluminum-doped zinc oxide thin films (ZnO:Al) were deposited on sodocalcic glass substrates by the chemical spray technique, using zinc acetate and aluminum pentanedionate as precursors. The effect of the [Al/Zn] ratio in the starting solution, as well as the substrate temperature, on the physical characteristic of ZnO:Al thin films was analyzed. We have found that the addition of Al to the starting solution decreases the electrical resistivity of the films until a minimum value, located between 2 and 3 at.%; a further increase in the [Al/Zn] ratio leads to an increase in the resistivity. A similar resistivity tendency with the substrate temperature was encountered, namely, as the substrate temperature is increased, a minimum value of around 475 °C in almost all the cases, was obtained. At higher deposition temperatures the film resistivity suffers an increase. After a vacuum-thermal treatment, performed at 400 °C for 1 h, the films showed a resistivity decrease about one order of magnitude, reaching a minimum value, for the films deposited at 475 °C, of 4.3 × 10^− 3 Ω cm.The film morphology is strongly affected by the [Al/Zn] ratio in the starting solution. X-ray analysis shows a (002) preferential growth in all the films. As the substrate temperature increases it is observed a slight increase in the transmittance as well as a shift in the band gap of the ZnO:Al thin films.     

Spray pyrolytic deposition of CuBiS2 thin films

Thin films of CuBiS₂ have been deposited on glass substrates using spray pyrolysis technique. The effect of substrate temperature on the growth of CuBiS₂ thin films is studied in the range of 150 to 400°C. The best quality films are grown at substrate temperature 250°C with 0·1 M composition. Other preparative parameters like spray rate, pressure, height of the solution, etc are optimized with respect to substrate temperature. Some optical and electrical properties of CuBiS₂ films are also studied and reported.     

Substrate temperature influence on ZnS thin films prepared by ultrasonic spray

ZnS thin films were deposited by ultrasonic spray technique. The starting solution is a mixture of 0.1 M zinc chloride as source of Zn and 0.05 M thiourea as source of S. The glass substrate temperature was varied in the range of 250 °C-400 °C to investigate the influence of substrate temperature on the structure, chemical composition and optical properties of ZnS films. The DRX analyses indicated that ZnS films have nanocrystalline hexagonal structure with (002) preferential orientation and grain size varied from 20 to 50 nm, increasing with substrate temperature. The optical films characterization was carried out by the UV-visible transmission. The optical gap and films disorder were deduced from the absorption spectra and the refractive indices of the films were determined by ellipsometric measurements. It is shown that the obtained films are generally composed of ZnO and ZnS phases with varied proportion, while at deposition temperature of 400 °C, they are near stoichiometric ZnS.     

不同衬底上低温生长的ZnO晶体薄膜的结构及光学性质比较

采用电子束反应蒸发方法,在单晶Si(001)及玻璃衬底上低温外延生长了沿c轴高度取向的单晶ZnO薄膜,并对沉积的ZnO晶体薄膜的结构和光学性质进行了分析比较。通过对ZnO薄膜的X射线衍射(XRD)分析及光致荧光激发谱(PLE)测量,研究了衬底材料结构特性、生长温度及反应气氛中充O     

Structure of vacuum deposited SnSe films

Tin selenide (SnSe) thin films prepared on mica and glass substrates by vacuum sublimation technique and examined by scanning electron microscopy and transmission electron diffraction techniques showed epitaxial and polycrystalline nature respectively irrespective of substrate temperature. Grain size of the films deposited on glass substrate increased with increase in substrate temperature.     

CdS薄膜的SILAR法制备与表征

采用液相薄膜制备工艺-SILAR(连续离子层吸附反应)法,在室温下于玻璃衬底上制备了CdS薄膜.对薄膜的表面形貌,薄膜的生长速率以及热处理与薄膜的成相及其电阻率的关系进行了观察和分析.实验结果表明:薄膜表面较致密,生长速率为2nm/cycle,随循环次数的增加,沉积粒子的尺寸趋于增大.室温下沉积的CdS薄膜为非晶态,经热处理后薄膜的结晶度提高,电阻率显著下降.此外,文章结合实验对薄膜的生长机理进行了初步的讨论.     

硅碳氧薄膜光学性能研究

硅碳氧(SiCO)薄膜是一种三元玻璃状化合物材料,具有热稳定性好、能带宽、折射率大、硬度高等特性,是一种具有潜在应用价值的新颖光学薄膜材料。本文采用射频磁控溅射技术在Si(100)及K9玻璃上制备了硅碳氧薄膜。利用椭圆偏振仪、紫外/可见/近红外光度计及X射线光电子能谱测试表征了薄膜的光学性能及薄膜组分。研究发现,通过改变基片温度、工作压强及溅射功率等工艺参数,所制备的硅碳氧薄膜均具有高折射率(大于1.80),相比之下,K9玻璃基硅碳氧薄膜的折射率有着更大的变化范围(1.84~2.20)。通过对K9玻璃基硅碳氧薄膜的光学透射性能研究表明,以硅碳氧陶瓷作为溅射靶材,采用射频磁控溅射技术在K9玻璃基上可以制备出,在可见光及近红外区域有着较好光学透射性能,平均透过率能到达83%的硅碳氧薄膜。     

Effect of aluminum and indium co-doping on zinc oxide films prepared by dc magnetron sputtering

Aluminum and indium co-doped zinc oxide (AIZO) thin films were prepared by direct current (dc) magnetron sputtering on glass substrate in pure argon atmosphere. Three inches of zinc oxide ceramic with 0.5 wt.% of aluminum and indium doping was used as a target in static mode. The influence of sputtering conditions i.e. substrate-target distance, pressure and power on AIZO films was studied. The electrical resistivity and microstructure of thin films were investigated by the four point probe technique and the scanning electron microscope, respectively. The optical transmittance of AIZO films was measured by UV visible spectrophotometer in the wavelength of 300-1100 nm. Depending on the deposited conditions, highly transparent films up to 80% with low resistivities in the range of 2.6-7.9 × 10^− 4 Ω cm were achieved at room temperature. Possible mechanism in the processing which, ultimately, determines the physical properties of AIZO films will be discussed.     

基片温度对TiO2薄膜表面形貌和性能的影响

利用射频磁控溅射设备在玻璃基片上制备TiO2薄膜,采用AFM、UV-Vis分光光度、接触角测定仪等测试手段,研究基片温度对薄膜表面形貌、粗糙度和表面性能的影响.结果表明,随着基片温度增加,薄膜表面粗糙度增大,薄膜中颗粒由无定形态逐渐向定向排列的晶态转变,而薄膜结构、表面形貌和粗糙度的变化明显影响薄膜表面性能.最后,探讨了薄膜的生长机理.     

离子束溅射制备CuInSe_2薄膜的研究

利用离子束溅射沉积技术,设计三元复合靶,直接制备CuInSe_2(CIS)薄膜.通过X射线衍射仪(XRD)、原子力显微镜(AFM)和分光光度计检测在不同衬底温度和退火温度条件下制备的CIS薄膜的微结构、表面形貌和光学性能.实验结果表明:使用离子束溅射沉积技术制备的CIS薄膜具有黄铜矿结构,在一定的条件下,适当温度的热处理可以制备结构紧密、颗粒均匀、致密性和结晶性良好的CIS薄膜,具有强烈的单一晶向生长现象.     

Effect of microstructural evolution on magnetic properties of Ni thin films

The magnetic properties of Ni thin films, in the range 20–500 nm, at the crystalline-nanocrystalline interface are reported. The effect of thickness, substrate and substrate temperature has been studied. For the films deposited at ambient temperatures on borosilicate glass substrates, the crystallite size, coercive field and magnetization energy density first increase and achieve a maximum at a critical value of thickness and decrease thereafter. At a thickness of 50 nm, the films deposited at ambient temperature onto borosilicate glass, MgO and silicon do not exhibit long-range order but are magnetic as is evident from the non-zero coercive field and magnetization energy. Phase contrast microscopy revealed that the grain sizes increase from a value of 30–50 nm at ambient temperature to 120–150 nm at 503 K and remain approximately constant in this range up to 593 K. The existence of grain boundary walls of width 30–50 nm is demonstrated using phase contrast images. The grain boundary area also stagnates at higher substrate temperature. There is pronounced shape anisotropy as evidenced by the increased aspect ratio of the grains as a function of substrate temperature. Nickel thin films of 50 nm show the absence of long-range crystalline order at ambient temperature growth conditions and a preferred [111] orientation at higher substrate temperatures. Thin films are found to be thermally relaxed at elevated deposition temperature and having large compressive strain at ambient temperature. This transition from nanocrystalline to crystalline order causes a peak in the coercive field in the region of transition as a function of thickness and substrate temperature. The saturation magnetization on the other hand increases with increase in substrate temperature.     

氧化钒薄膜在玻璃基片上的生长研究

采用直流反应磁控溅射法, 在平整光滑的普通玻璃基片表面沉积了厚度分别为80nm、440nm和1μm的氧化钒薄膜. 采用原子力显微镜(AFM)、扫描电镜(SEM)和X射线衍射仪(XRD)对薄膜的表面形貌、结构和结晶化的分析表明, 厚度影响着薄膜的颗粒大小和结晶状态, 随着薄膜厚度的增加, 薄膜的颗粒增大, 晶化增强; 薄膜具有明显的垂直于衬底表面的“柱”状择优生长特征. 对薄膜的方阻和方阻随温度的变化进行了相关分析, 证实了厚度对氧化钒薄膜的电学性能存在明显的影响, 随着薄膜厚度的增加, 薄膜的方阻减小, 方阻温度系数升高, 薄膜的方阻随温度变化的回线滞宽逐渐增大, 薄膜的金属-半导体相变逐渐趋于明显.     

Effect of interface energy on abnormal grain growth in pyrite films prepared by sol-gel method

The pyrite films were prepared on quartz and glass substrates by the sol-gel dip coating process and sulfuration treatment. The film microstructure, chemical composition and morphology dependent on sulfuration temperature were investigated. The sulfuration treatment at 773-923 K for the films prepared by the sol-gel dip coating process can prepare pyrite films. Some grains show abnormal growth during sulfuration treatment. The grain size of abnormal growth increased to a limited value with increasing the sulfuration temperature. The grain size in pyrite films has bimodal distribution. The first peak is of Lognormal distribution and the second peak Gauss distribution. By determination of the abnormal grain growth activation energy, it can be concluded that the reduction in interface energy at the interface between the substrate and film should be responsible for the grain abnormal growth.     

Indium doped ZnO films prepared by RF magnetron sputtering: effect of substrate temperature on the strain-induced band gap

Indium doped zinc oxide (InZnO) thin films were deposited onto corning glass substrates by RF magnetron sputtering. The dependence of crystal structure, surface morphology, optical properties and electrical conductivity on substrate temperature was investigated using XRD, AFM, UV-vis Spectrophotometer, Fluorescence Spectrophotometer and four-point probe. The films were prepared at different substrate temperatures viz, room temperature (RT), 473 K and 673 K at RF power 200 W. All the films showed preferred orientation along (002) direction. Crystallite size increased from 14 to 19 nm as the substrate temperature was increased to 473 K. With increase in substrate temperature the crystallites did not show any further growth. AFM analysis showed that the rms roughness value decreased from 60 nm to 23 nm when the substrate temperature was increased to 673 K. Optical measurements revealed maximum band gap and minimum refractive index for the film prepared at 473 K. A strong correlation between the band gap variation and the strain developed at different substrate temperatures is established.     

基底温度对直流磁控溅射制备氮化铜薄膜的影响研究

采用反应直流磁控溅射镀膜法,在氮气分压为0.9Pa、不同基底温度下、玻璃基底上制备了纳米多晶Cu3N薄膜,并研究了基底温度对薄膜结构和性能的影响。结果表明,当基底温度为100℃及以下时,薄膜以[111]方向择优生长为主;在150℃及200℃时,薄膜以[100]方向择优生长为主;250℃时开始出现Cu的[111]方向生长,300℃时已完全不能形成Cu3N晶体,只有明显的Cu晶体。随基底温度的升高,薄膜的沉积速率在13～28nm/min呈U型变化,低温和高温时较高,150℃时最低;薄膜的电阻率显著降低;薄膜的显微硬度先升后降,100℃时显微硬度最大。     

真空蒸镀聚乙烯醇薄膜

采用真空蒸发沉积(蒸镀)聚乙烯醇薄膜,通过SEM和光学显微镜观察聚乙烯醇薄膜呈现典型的岛状形式并均匀分布于衬底表面,且以梯田状台阶式长大.衬底温度是影响PVA薄膜沉积速度的主要因素.红外光谱分析表明其蒸镀薄膜的主要化学结构特点是羰基代替了部分羟基.     

电子束蒸发制备CdS多晶薄膜及性质研究

采用电子束蒸发工艺在普通玻璃衬底上制备了硫化镉(CdS)多晶薄膜,研究了不同衬底温度对薄膜结构、表面形貌及光透过率的影响.测试结果显示:(1)不同衬底温度下沉积的CdS薄膜均呈现了〈002〉晶向的高度优势生长,属于六方相结构.随着衬底温度的升高,还逐渐出现了〈103〉、〈004〉、〈105〉等六方晶向;(2)CdS多晶薄膜表面连续,致密性好,且晶粒大小随着衬底温度的升高而增大;(3)低温下制备CdS薄膜吸收谱有较宽的吸收边,随着衬底温度的升高,吸收曲线趋于陡直.制备样品在550nm波段后的平均透过率都超过70%,符合作为CdTe太阳电池的窗口层.     

Highly conducting and transparent tin-doped CdO thin films for optoelectronic applications

Highly conducting and transparent thin films of tin-doped cadmium oxide were deposited on quartz substrate using pulsed laser deposition technique. The effect of growth temperature on structural, optical and electrical properties was studied. These films are highly transparent (78-89%) in visible region, and transmittance of the films depends on growth temperature. It is observed that resistivity increases with growth temperature after attaining minimum at 150 °C, while carrier concentration continuously decreases with temperature. The lowest resistivity of 1.96 × 10^− 5 Ω cm and carrier concentration of 5.52 × 10²¹ cm³ is observed for the film grown at 150 °C. These highly conducting and transparent tin-doped CdO thin films grown via pulsed laser deposition could be an excellent candidate for future optoelectronic applications.