磁控溅射MgxZn1-xO薄膜的结构与光学性能研究

利用射频磁控溅射技术在玻璃衬底上沉积了MgxZn1-xO(x=0～0.2)薄膜.采用X射线衍射仪、紫外-可见光分光光度计和荧光光谱仪研究了Mg掺杂量对MgxZn1-xO薄膜结构与光学性能的影响.XRD图谱表明,MgxZn1-xO薄膜均为六角纤锌矿结构,并且呈现出C轴择优生长特性,当x>0.1时薄膜出现(100)面衍射峰,薄膜的c轴择优生长特性减弱,随着x值的增加,晶格常数c逐渐减小.紫外可见光透射光谱表明,Mg的掺入提高了薄膜在可见光范围内的透过率,同时使薄膜的禁带宽度增大.PL谱分析显示,Mg的掺入使薄膜的紫外发射峰和蓝光发射带发生蓝移,当x=0.1时近带边发射峰与杂质发射的强度比值最高.     

化学水浴法制备In2S3薄膜的组织和性能研究

采用化学水浴(CBD)法在InCl3·4H2O和CH3CSNH2的酸性混合溶液体系中分别通过改变pH值、溶液nIn∶nS浓度比及溶液温度参数依次制备In2S3薄膜,并通过X射线衍射、扫描电镜及紫外/可见/近红外分光光度计等手段系统研究不同工艺下制备In2S3薄膜的晶相结构、表面形貌及光学性能.研究发现:溶液pH值对制备In2S3薄膜有很大的影响,在pH为1.8制备的In2S3薄膜性能较好;溶液nIn∶ns浓度比影响薄膜的致密性,在1∶4时相对较好;CBD法制备薄膜最佳溶液温度为80℃.在优化工艺参数下制备的In2S3薄膜可见光透过率在90％以上,禁带宽度为2.72eV,能够满足CIGS太阳能电池缓冲层薄膜的要求.     

Co掺杂量对ZnO薄膜结构及光学特性的影响

采用脉冲激光沉积法(PLD)在SiO2村底上成功制备了具有c轴择优生长特性的Zn1-xCoxO(x=0.05、0.1、0.2、0.3)系列薄膜.通过X射线衍射和能谱仪研究了Co掺杂量对薄膜晶体结构和成分的影响;同时利用光致发光谱(PL)和透过率研究了薄膜的光学特性.结果表明,当掺杂浓度为10%时,薄膜生长最好,c轴择优生长最为显著;Co元素的掺入改变了薄膜的紫外、绿光和蓝光发射,分析认为主要是Co元素的掺入量改变了薄膜的禁带宽度、氧错位缺陷浓度和锌填隙缺陷的浓度;Co元素掺杂浓度为5%时,薄膜的透过率超过90%.此外,探讨了不同波段光发射的可能机理.     

Cu/In原子比及硫化温度对于CuInS2薄膜性能影响

采用中频交流磁控溅射方法,在玻璃基底上沉积Cu-In预制膜,采用固态硫化法制备获得了CuInS2(CIS)吸收层薄膜.考察了预制膜Cu/In原子比及硫化温度对于CIS薄膜结构及禁带宽度影响.通过XRD及Raman光谱分析了薄膜结构,通过近红外透过曲线得出薄膜禁带宽度.结果表明,随着预制膜中Cu与In原子比(Cu/In)及硫化温度不断升高,薄膜CuAu(CA)相含量逐渐降低,黄铜矿(CH)相逐渐升高,薄膜结晶性逐渐改善.600℃以上硫化时薄膜中主要存在CH相CuInS2.薄膜禁带宽度随着预制膜中Cu/In原子比及硫化温度不断升高而升高,Cu/In原子比为1.05,硫化温度为500℃时薄膜禁带宽度可达1.40eV.     

基底温度对直流溅射Nb掺杂TiO2薄膜性能的影响

采用陶瓷靶直流磁控溅射,以玻璃为基底制备2.5wt%Nb掺杂TiO2薄膜,控制薄膜厚度在300~350 nm,研究了不同基底温度下所制得薄膜的结构、形貌和光学特性.XRD分析表明,基底温度为150℃、250℃和350℃时,薄膜分别为非晶态、锐钛矿(101)和金红石相(110)结构.基底温度250℃时,锐钛矿相薄膜的晶粒尺寸最大,约为32 nm.薄膜表面形貌的SEM分析显示,薄膜粗糙度和致密度随基底温度升高得到改善.薄膜的平均可见光透过率在基底温度为250℃以内约为70%,随基底温度升高至350℃,平均透过率下降为59%,金红石相的存在不利于可见光透过.Nb掺杂TiO2薄膜的光学带宽在3.68~3.78 eV之间变化.基底温度为250℃时,锐钛矿相薄膜的禁带宽度最大,为3.78 eV.     

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.     

基于透反射光谱确定Te/TeO_2-SiO_2复合薄膜的光学常数

基于电化学诱导sol-gel方法制备Te/TeO_2-SiO_2复合薄膜的紫外-近红外投射光谱实验,采用透反射光谱测量法推导出Te/TeO_2-SiO_2复合薄膜在200~1100nm波长范围内的光学常数,包括光学透过率、反射率、线性吸收系数、消光系数、线性折射率及禁带宽度。研究发现,复合薄膜具有高折射率(1.93~2.03),测试波长为1064nm,低吸收和禁带宽度宽(3.07~3.40eV)等光学特性,同时薄膜的光学常数对制备过程中的重要参数制备电压表现出强烈的依赖性,制备电压越大薄膜的光学透过率降低,薄膜厚度增大,线性折射率增大。     

Al-Sn共掺杂ZnO薄膜的结构与光电性能研究

采用射频磁控共溅射法在玻璃衬底上制备出了Al与Sn共掺杂的ZnO(ATZO)薄膜.在固定ZnO∶Al(AZO)靶溅射功率不变的条件下,研究了Sn靶溅射功率对ATZO薄膜的结晶质量、表面形貌、电学和光学性能的影响.结果表明,制备的ATZO薄膜是六角纤锌矿结构的多晶薄膜,具有c轴择优取向,而且表面致密均匀.当Sn溅射功率为5W时,330 nm厚度的ATZO薄膜的电阻率最小为1.49×10-3 Ω·cm,比AZO薄膜下降了22％.ATZO薄膜在400～900 nm波段的平均透过率为88.92％,禁带宽度约为3.62 eV.     

Bi3.45Eu0.55Ti3O12铁电薄膜的光学性能

采用化学溶液沉积法在石英衬底上制备了Bi3.45Eu0.55Ti3O12(BEuT)铁电薄膜,研究了BEuT薄膜的结构和光学性能。XRD测试结果表明,BEuT薄膜皆形成铋层状钙钛矿型结构,其晶粒尺寸随着退火温度的提高而增加。薄膜的光学透过率曲线显示,在大于500nm的波段BEuT的透过率比较高,而其禁带宽度大约为3.61eV。BEuT薄膜的发光强度随着退火温度的提高,先是增强后减弱,在700℃时达到最大。这与薄膜的结晶状况有关。     

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。     

Chemical bath deposition of CdS thin films doped with Zn and Cu

Zn- and Cu-doped CdS thin films were deposited onto glass substrates by the chemical bath technique. ZnCl₂ and CuCl₂ were incorporated as dopant agents into the conventional CdS chemical bath in order to promote the CdS doping process. The effect of the deposition time and the doping concentration on the physical properties of CdS films were investigated. The morphology, thickness, bandgap energy, crystalline structure and elemental composition of Zn- and Cu-doped CdS films were investigated and compared to the undoped CdS films properties. Both Zn- and Cu-doped CdS films presented a cubic crystalline structure with (1 1 1) as the preferential orientation. Lower values of the bandgap energy were observed for the doped CdS films as compared to those of the undoped CdS films. Zn-doped CdS films presented higher thickness and roughness values than those of Cu-doped CdS films. From the photoluminescence results, it is suggested that the inclusion of Zn and Cu into CdS crystalline structure promotes the formation of acceptor levels above CdS valence band, resulting in lower bandgap energy values for the doped CdS films.     

Effect of the substrate temperature on the structural, optical and electrical properties of spray-deposited CdS:B films

Boron doped CdS films have been deposited by spray pyrolysis method onto glass substrate temperature in the range of 350–450 °C. And the effect of substrate temperature (T _s) on the structural, electrical and optical properties of the films were studied. The structural properties of boron doped CdS films have been investigated by (XRD) X-ray diffraction techniques. The X-ray diffraction spectra showed that boron doped CdS films are polycrystalline and have a hexagonal (wurtzite) structure. By using SEM analysis, the surface morphology of the films was observed as an effect of the variation of substrate temperature. The substrate temperature is directly related with the shift detected in the band gap values derived from optical of parameters and the direct band gap values were found to be in the region of 2.08–2.44 eV. The electrical studies showed that the film deposited at the substrate temperature 400 °C had high carrier concentration and Hall mobility and minimum resistivity. This resistivity value decreased with increase in temperature up to 400 °C indicating the semiconducting nature of B- doped CdS films. The lattice parameter, grain size, microstrain and dislocation densities were calculated and correlated with the substrate temperature (T _s ).     

薄膜太阳电池缓冲层硫化镉的制备

采用操作简单的化学水浴法(CBD)在普通载玻片上制备了太阳能电池用缓冲层硫化镉薄膜。通过改变反应温度、溶液p H值和退火温度等实验条件,探讨了硫化镉薄膜的最佳制备工艺条件,并利用X射线衍射仪、紫外-可见-分光光度计和电化学工作站对生成的薄膜样品进行了表征。结果表明,制备均匀性好、致密、覆盖度好的硫化镉薄膜的最佳实验条件如下:反应温度为70℃,溶液p H值为10,且后续在350℃温度下进行热处理1 h。此条件下得到的硫化隔薄膜的可见光透过率较高,具有明显的光电导现象;通过计算,最优实验条件下获得薄膜的禁带宽度为2.3 5 e V,与理论值2.42 e V很接近。     

Multiple dip deposition of CdS films prepared by oscillating chemical bath

Highly oriented CdS thin films with thicknesses greater than 1 μm were deposited using the oscillating chemical bath deposition technique with multiple dips at 75 °C, and from 15 to 75 min as deposition times. Samples with different thicknesses were deposited by repeating the chemical deposition process one, two and three times. All CdS films present the α-greenockite hexagonal structure with (002) as the preferential orientation. Band-gap energy values ranged from 2.35 to 2.42 eV, being the smaller value for the two dip processes. Energy dispersion spectroscopy measurements show good stoichiometry of the CdS films with 4.3 at.% as the maximum Cd variation.     

ZrO2:CdS薄膜的光物理性质

利用吸收和荧光光谱研究了ＺｒＯ_２：ＣｄＳ薄膜的光物理特性．实验观察到了随颗粒尺寸的减小ＣｄＳ的吸收带边的蓝移现象．研究了不同激发条件下的荧光光谱,发现了薄膜中ＣｄＳ的微弱的荧光发射．并且分析了介质效应对ＣｄＳ光学特性的影响．     

Correlation on compositional change with crystal structure and optical property of CdS thin films grown by femtosecond pulsed laser

The effect of compositional change with the crystal structure and optical property of CdS films synthesized by femtosecond pulsed laser deposition has been studied. The results indicate that growth temperature played an important role on compositional change, crystal structure and optical properties of the CdS films. And the compositional segregation of the CdS films could be drawn from the selective evaporation of sulfur from the film surface as a result of heating up the substrates.     

Oxygen interaction with CdS based gas sensors by varying different preparation parameters

The interaction of oxygen gas atmosphere with CdS films prepared by spray pyrolysis is studied. Spray time and deposition temperature are taken as variable parameters. The prepared film structure is characterized by XRD to elucidate the film crystallinity nature and size. Both thickness and crystallite size of the CdS films decrease as the deposition temperature increases from 340 to 490 °C at constant deposition time. The opposite trend was observed when the films are deposited at different deposition times and constant deposition temperature. The films are exposed to different concentrations of oxygen and the thinner CdS films show higher sensitivity and a shorter response time than the thicker films. The results obtained are promising to use the prepared films for detecting oxygen.     

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.     

Optical and structural investigations on spray-deposited CdS films

CdS and indium doped CdS thin films have been prepared by the spray pyrolysis method. The optical band gaps of CdS and doped CdS were found to be 2.35 and 2.39 eV, respectively. The carrier concentration of doped CdS, calculated from an optical method, was found to be 7.5×1018 cm-3. The X-ray diffraction (XRD) analysis revealed that the films were polycrystalline and exhibited hexagonal structure. In order to calculate theoretical XRD intensity values for CdS, the structure factor F(hkl)2 was derived. The temperature correction factor was employed for both Cd and S to correct intensity values. The theoretically calculated XRD intensity values of (hkl) coincided with those of experimental values. © 1998 Kluwer Academic Publishers