化学沉积参数对CdS薄膜前驱物利用率的影响

采用化学水浴法,在醋酸镉、硫脲、氨水、醋酸铵的体系中制备CdS薄膜,设计L2556正交实验,研究了各沉积参数对前驱物利用率的影响.结果表明,随前驱物醋酸镉、硫脲各自浓度的增加,其自身的利用率下降,但另一方的利用率上升.前驱物的利用率随络合剂醋酸铵浓度的增加先增大后减小,随氨水浓度的增加先减小后增大;其利用率随反应条件温...     

化学水浴沉积时间对CdS薄膜性质的影响

采用CBD法在醋酸镉溶液体系中制备CdS半导体薄膜,通过XRD、XRF、SEM和光学透过率谱等测试手段研究了沉积时间对CdS薄膜沉积过程和性质的影响.结果表明,随着沉积时间的增加,薄膜增厚;S/Cd原子比增加,但都为富Cd的CdS薄膜;XRD研究表明,薄膜结构由立方、六方混合相向立方相转变,(111)方向成为择优生长方向;SEM研究表明,随沉积时间增加,薄膜变致密,薄膜表面出现的白色附着颗粒增多,尺寸增大;沉积时间对薄膜的光学性质也有很大的影响,随着沉积时间的增加薄膜透过率减小,而禁带宽度值增大.     

络合剂对化学水浴沉积 ZnS薄膜的影响

采用不同络合剂化学水浴沉积ZnS薄膜,应用台阶仪、SEM、XRD、波谱仪等手段测定了ZnS薄膜的厚度、表面、物相结构及透过率等.结果表明,氨水体系沉积薄膜速度明显慢于另外两种体系,沉积的ZnS薄膜都为立方结构.柠檬酸钠体系沉积的ZnS 薄膜结晶和透过率最佳,但薄膜表面缺陷较多;氨水-联氨体系沉积的ZnS薄膜表面质量最佳,结晶和透过率也较好;氨水体系沉积的ZnS薄膜质量较差.用3种体系沉积的ZnS薄膜用于制备铜铟镓硒Cu(In,Ga)Se2太阳电池,氨水和氨水-联氨体系沉积的ZnS薄膜制备的电池转换效率明显高于柠檬酸钠体系沉积的ZnS制备的太阳电池.     

La掺杂对CdS薄膜性能的影响

采用化学水浴法在玻璃衬底上制备了纯CdS薄膜和稀土La掺杂的CdS薄膜,在氮气气氛中对薄膜进行热处理.结果表明,未掺杂样品为立方闪锌矿CdS,La掺杂后衍射强峰仍为立方闪锌矿(111)晶向,但出现了微弱的六方纤锌矿结构,而且增强了短波光和近红外光的透过率,禁带宽度明显减小,同时La的掺入促进S元素百分含量的增加,使Cd/S更接近化学计量比.     

Dy掺杂的CdS薄膜的制备及性能分析

采用化学水浴法在玻璃衬底上制备纯的和稀土Dy掺杂的CdS薄膜,并在N2气氛中,对以上制备的薄膜进行T=350℃、t=40min的热处理.实验结果表明,水浴温度在70℃～80℃间制备的CdS薄膜,表面致密、光滑,膜的质量最好,且为沿[111]晶向择优生长的立方闪锌矿结构.掺Dy虽未改变CdS薄膜的晶体结构,但改善了薄膜的表面形貌,使得薄膜的致密性增强、颗粒大小匀称,同时Dy的掺入增大了CdS薄膜在可见光范围内的透光率.     

温度对化学水浴法制备ZnS薄膜的影响

采用化学水浴法在玻璃上制备了太阳能电池中的ZnS缓冲层。采用SEM、EDS、XRD和nkd-分光光度计等手段研究了水浴温度对ZnS薄膜的表面形貌、结构和光学性能的影响。结果表明,升高温度不能明显改变薄膜的结晶性、形貌和沉积生长方式,能否成膜与温度的关系也不大,但成膜速率对温度的依赖性较大。随温度的升高,薄膜的透过率先减小后增大,反射率则先增大后减小。对同一试样而言,透过率和反射率对应较好。当温度为70℃时,可制得禁带宽度为3.83eV、符合化学计量比、平整的非晶ZnS薄膜。     

CdS纳米晶薄膜的制备及光电性能研究

利用化学浴沉积法,以N(CH2CH2OH)3为络合剂,Cd(CH3COO)2·2H2O和(NH2)2CS为前驱体溶液制备了CdS纳米晶薄膜,利用FESEM、XRD考察了前驱体浓度、络合剂浓度、前驱体溶液的pH值、反应温度等因素对CdS纳米晶薄膜的表面形貌、晶粒大小及晶体结构的影响,在最佳工艺条件下可以制得表面平整,结构致密的CdS纳米晶薄膜。UV-Vis光谱表明CdS在短波长区域有较强的吸收,符合作为窗口材料和过渡层的要求;光电性能测试表明CdS具有较好的光电响应,呈特征n型半导体特性。     

电解液pH值对电化学法制备的CIGS薄膜光电性能的影响

以F 掺杂透明导电玻璃(FTO)为基底, 利用一步电化学沉积法制备了Cu(In_1-x,Ga_x)Se₂(CIGS)薄膜, 系统地研究了电解液pH值对CIGS薄膜的化学组分、结构及其光电性能的影响。结果显示通过改变电解液pH值可以有效调控薄膜中In和Ga的化学计量比。X射线衍射(XRD)分析和扫描电子显微镜(SEM)结果表明, pH值为2.0时制备的CIGS薄膜结晶性较好, 颗粒尺寸分布均匀。并且利用表面光伏技术研究了不同化学计量比对CIGS薄膜中光电荷动力学过程的影响, 结果表明n(Ga)/n(In+Ga)约为0.3时, CIGS薄膜的光电性能最好。     

CdS薄膜的生长和结构分析

使用化学浴沉积(CBD)在硫酸镉-硫脲的氨溶液中,成功地制备出了高质量的CdS薄膜.用扫描电境(SEM)、X射线衍射(XRD)及紫外-可见-近红外光谱仪对其进行了测试分析,结果表明,NH3摩尔浓度对生成CdS薄膜的表面致密性影响很大,当NH3摩尔浓度比较大时,无法生成连续致密的胶体颗粒薄膜,反应体系中S2-和Cd2 溶液的摩尔浓度增加,CdS胶体粒度增大.在相同NH3摩尔浓度下,随着S2-和Cd2 摩尔浓度比值([S2-]/[Cd2 ])的增大,CdS胶体粒子粒度减小;透过光谱的峰位随着胶体粒子尺寸的减小向短波方向移动,当NH3摩尔浓度变化时,在一定的范围内改变CdS膜的透过率.将化学浴沉积(CBD)过程的研究从薄膜厚度优化改进为胶体粒子尺寸优化,促进了CBD技术的发展.     

化学超声水浴沉积法制备CdSe薄膜及其性能的研究

以CdCl2.2.5H2O为镉源,Na2SeSO3为硒源,柠檬酸钠为络合剂,采用化学超声水浴沉积法制备了CdSe薄膜,用XRD、UV-Vis、SEM等方法进行表征,结果表明,所制备的薄膜为n型半导体,在可见光区有一定的吸收,可以获得较好的光电流。应用化学超声水浴沉积法制备CdSe薄膜的优化条件为：络合剂比例1：1.5、镉与硒浓度比例2.5：1、PH值10、沉积时间2.5h、退火温度350℃。     

pH值对合成聚苯丙炔酸的影响

苯丙炔酸上的羧基起到终止剂的作用,限制了苯丙炔酸的聚合。加入NaOH将单体转化成钠盐,聚合后用HCl酸化成聚苯丙炔酸。单体由肉桂酸和液溴通过先加成后消去反应制得。利用红外光谱、紫外光谱、荧光光谱、凝胶渗透色谱和TGA对单体及聚合物的结构和性能进行了表征,2212cm-1处C≡C键伸缩振动特征吸收峰消失形成1602cm-1C—C键伸缩振动特征峰,表明了聚合物的合成。荧光光谱显示聚苯丙炔酸在375nm激发波长下发蓝光,于465nm处有特征荧光发射峰,与没有加NaOH聚合的聚合物相比较,紫外吸收波长范围更大,加碱聚合的聚苯丙炔酸分子量能达到10552,TGA测试结果表明聚苯丙炔酸具有一定的热稳定性。     

Effects of low temperature on the characteristics of tantalum thin films

In this paper the effects of substrate temperature (room temperature - 350 °C) on the phase composition and crystallization orientation of the tantalum thin film deposited by direct current magnetron sputtering in an extremely low power deposition regime are presented. In this experiment, heating the substrates to 350 °C resulted in the growth of the hard and brittle tetragonal crystalline structure (β-Ta). Deposited tantalum has a conical structure with large voided boundaries. Sheet resistance of samples is much larger than for the convenient conductors which decreased with increasing the substrate temperature.     

Effects of low temperature on the characteristics of tantalum thin films

In this paper the effects of substrate temperature (room temperature – 350 °C) on the phase composition and crystallization orientation of the tantalum thin film deposited by direct current magnetron sputtering in an extremely low power deposition regime are presented. In this experiment, heating the substrates to 350 °C resulted in the growth of the hard and brittle tetragonal crystalline structure (β-Ta). Deposited tantalum has a conical structure with large voided boundaries. Sheet resistance of samples is much larger than for the convenient conductors which decreased with increasing the substrate temperature.     

Effect of calcination and pH value on the structural and optical properties of titanium oxide thin films

Titanium oxide thin films on glass and silicon wafer substrates were prepared by the sol-gel process. The pH variation and the calcination effect on the optical and structural properties of the films were systematically examined. The coated films were characterized by atomic-force microscopy (AFM), NKD analyzer, X-ray diffraction (XRD) and cyclic voltammograms (CV). The influence of calcination and pH value on the spectra of transmittance, reflectance, and refractive indices and on the surface structure has been investigated. From X-ray diffractometric measurements (XRD), it has been confirmed that the films are an anatase form. The effects of pH and surface modification of titanium oxide were studied with AFM images. These showed that the surface texture was changed dramatically according to calcinations and pH variation. Spectral dependencies of refractive indices (n) were determined for all films. Band-gap energy (E_g) was also estimated for these films.     

Effects of pH value and temperature of solution on the removal efficiency of support material

Removing support material from rapid prototyping part fabricated by fused deposition modeling is required when the object is completed. Removing support material from rapid prototyping part system rapidly and efficiently is an important concern because the product life cycle is shorter than before. Effects of pH value and temperature of solution on the removal efficiency of support material were investigated in this study. Both pH value and temperature of the solution contribute to the removal efficiency of support material. The saving in the removing time of up to 83.4% is achieved by integrating two effects. The trend equation of y = 293.42x + 544.72 is capable of predicting the removing time. Removing time (y) can be predicted directly from the volume of support material (x). The error rate can be controlled within 5.11%. Surface roughness improvement rate of up to 46.3% is achieved using the solution with a pH value of 13 and a temperature of 95°C.     

pH值对液相自组装法制备纯相BiFeO3薄膜的影响

采用液相自组装法,Bi(NO3)3·5H2O,Fe(NO3)3· 9H2O为原料,柠稼酸为螯合剂,以OTS单分子层为模板,在ITO玻璃基片上成功制备了BiFeO3晶态薄膜.研究了前驱液pH值对BiFeO3薄膜的影响.利用XRD,EDS和SEM等测试手段对在不同pH值下沉积的BiFeO3薄膜进行了表征.结果表明,由于Bi...     

Effect of pH on the formation-dissolution processes of anodic films on bismuth

Interrupted polarization measurements indicate that among Na₂SO₄, buffer (pH 7) and NaOH, the most passivating anodic film is formed on bismuth in the buffer solution. Under opencircuit conditions, film growth occurs on the metal surface in buffer solutions of pH 1.81 to 11.25. The rate of growth increases with decrease in pH. The passive metal undergoes dissolution in buffer solutions according to a zero-order mechanism; the most effective pH values for film dissolution lie between 8 and 10. The results indicate the simultaneous importance of the anion type and pH of the electrolyte in determining anodic film stability.     

Effects of substrate roughness on infrared-emissivity characteristics of Au films deposited on Ni alloy

Low-emissivity Au thin films were sputter-deposited on three groups of nickel alloy substrates with different surface roughness for high-temperature application. After deposition, the samples were heated in air at 600 °C for 200 h to simulate the application environment. The results showed that the substrate roughness had great influences on infrared-emissivity characteristics of the Au films. The average infrared emissivity of the samples with small roughness just increased a little after heat treatment, while it greatly increased for the sample with large roughness. Increasing the roughness of the samples will not only increase the effective surface emitting area, but also become a detriment to the integrity of Au films.     

Influence of pH on electrochemically deposited CdSe thin films

Polycrystalline CdSe thin films have been electrodeposited at room temperature on stainless steel (ss) and fluorine doped tin oxide (FTO) coated glass substrate from aqueous electrolytes containing salts of cadmium acetate and selenium dioxide. The pH of the bath is varied from 1.75, at the interval of 0.25, to 3. The effect of pH on the photoelectrochemical (PEC), structural and optical properties of the deposited film is studied. The pH of the bath is optimized by the PEC technique and is observed to be 2.75. The analysis of the XRD patterns show that the deposited CdSe material is polycrystalline with a hexagonal crystal structure. SEM study shows that the total substrate surface is well covered by uniformly distributed spherical shaped grains. The optical absorption studies reveal that the pH of the electrolytic solution has a significant effect on the band gap of the CdSe thin film. The transition involved is direct with band gap energy E_g of 1.72 eV.