Magnetron sputtered transparent conducting CdO thin films

Thin films of cadmium oxide have been produced by dc reactive magnetron sputtering in nitrogen and oxygen atmosphere. The structural, optical, and electrical characterization of these films are investigated. Structural analysis indicates that the films are polycrystalline and cubic. Composition analysis by Rutherford backscattering spectrometry has been made and it is found that the films contain excess cadmium and deficient oxygen. It is observed from the optical properties that the films possess a transmittance of about 85% in the visible and near infrared regions of the spectrum and direct bandgap values in the range 2.50 to 2.68 eV for films of thicknesses 146 to 177 nm. Electrical measurements point out that the films have resistivity, carrier concentration, and mobility in the range 2.65 to 6.64 × 10^-6 Ωm, 1.60 to 2.35 × 10²⁶ m^-3, and 57.65 to 100.48 × 10⁻⁴ m² v⁻¹ s⁻¹ respectively.     

NZO透明导电薄膜的制备及其性能研究

室温下,采用直流磁控溅射法,在玻璃衬底上制备出Nb掺杂ZnO(NZO,ZnO:Nb)透明导电薄膜。研究了靶与衬底之间的距离对NZO薄膜结构、形貌、光学及电学性能的影响。实验结果表明,不同靶基距下制备的NZO薄膜均为c轴择优取向生长,(002)衍射峰的强度随着靶基距的减小而增大。靶基距增大时,薄膜表面逐步趋向平整光滑、均匀致密,薄膜的厚度逐渐减小。在靶基距为60mm时,制备的薄膜厚为355.4nm,电阻率具有最小值(6.04×10-4Ω.cm),在可见光区的平均透过率达到92.5%,其光学带隙为3.39eV。     

射频磁控溅射法制备掺锆氧化锌透明导电薄膜

利用射频磁控溅射法在室温下制备出了掺锆氧化锌(ZnO∶Zr)透明导电薄膜。研究了溅射压强对ZnO∶Zr薄膜表面形貌、结构、光学和电学性能的影响。结果表明:ZnO∶Zr薄膜为六角纤锌矿结构的多晶薄膜,且具有c轴择优取向,溅射压强对薄膜电阻率有显著影响,压强为1.5Pa时,电阻率具有最小值1.77×10–3Ω·cm。所制备的ZnO∶Zr薄膜具有良好的附着性能,在可见光区平均透过率超过93%。     

电子束反应蒸发制备高迁移率IMO薄膜及其性能研究

研究了掺杂剂含量对电子束反应蒸发技术生长掺钼氧化铟（In2O3：Mo,IMO）薄膜的微观结构以及光学和电学性能的影响。采用高纯度In2O3：MoO3陶瓷靶和O2作为源材料。随着MoO3掺杂剂含量的增加,IMO薄膜电阻率先降低而后增加,光学性能呈现薄膜透过率下降的趋势。在1.0 wt.%MoO3掺杂剂含量时,获得最佳薄膜...     

掺铝ZnO透明导电薄膜的制备及光电性能研究

采用RF磁控溅射法制备了掺铝ZnO(AZO)透明导电薄膜,用X射线衍射仪、分光光度计和四探针仪等,研究了沉积温度对薄膜晶体结构和光电性能的影响。结果表明,AZO薄膜为六方纤锌矿结构的多晶膜,具有(002)择优取向。沉积温度对薄膜的择优取向程度、晶粒尺寸、透射率和导电性能等具有明显的影响。当沉积温度为400℃时,AZO薄膜最大晶粒尺寸为37.21nm、可见光范围平均透射率为85.5%、优良指数为1.30×10-2?-1。     

Patterning of transparent conducting oxide thin films by wet etching for a-Si:H TFT-LCDs

The patterning characteristics of the indium tin oxide (ITO) thin films having different microstructures were investigated. Several etching solutions (HC1, HBr, and their mixtures with HNO₃) were used in this study. We have found that ITO films containing a larger volume fraction of the amorphous phase show higher etch rates than those containing a larger volume fraction of the crystalline phase. Also, the crystalline ITO films have shown a very good uniformity in patterning, and following the etching no ITO residue (unetched ITO) formation has been observed. In contrast, ITO residues were found after the etching of the films containing both amorphous and crystalline phases. We have also developed a process for the fabrication of the ITO with a tapered edge profile. The taper angle can be controlled by varying the ratio of HNO₃ to the HC1 in the etching solutions. Finally, ITO films have been found to be chemically unstable in a hydrogen containing plasma environment. On the contrary, aluminum doped zinc oxide (AZO) films, having an optical transmittance and electrical resistivity comparable to ITO films, are very stable in the same hydrogen containing plasma environment. In addition, a high etch rate, no etching residue formation, and a uniform etching have been found for the AZO films, which make them suitable for a-Si:H TFT-LCD applications.     

Microstructure and optoelectronic properties of gallium- titanium-zinc oxide thin films deposited by magnetron sputtering

Gallium-titanium-zinc oxide(GTZO) transparent conducting oxide(TCO) thin films were deposited on glass substrates by radio frequency magnetron sputtering. The dependences of the microstructure and optoelectronic properties of GTZO thin films on Ar gas pressure were observed. The X-ray diffraction(XRD) and scanning electron microscopy(SEM) results show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. With the increment of Ar gas pressure, the microstructure and optoelectronic properties of GTZO thin films will be changed. When Ar gas pressure is 0.4 Pa, the deposited films possess the best crystal quality and optoelectronic properties.     

Low-temperature deposition of transparent conducting Mn-W co-doped ZnO thin films

Mn-W co-doped ZnO(ZMWO) thin films with low resistivity and high transparency were successfully prepared on glass substrate by direct current(DC) magnetron sputtering at low temperature.The sputtering power was varied from 65 to 150 W.The crystallinity and resistivity of ZMWO films greatly depend on sputtering power while the optical transmittance and optical band gap are not sensitive to sputtering power.All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientat...     

ZnO∶Ti透明导电薄膜的制备与光电性能研究

采用直流磁控溅射法,在水冷7059玻璃衬底上制备了具有高透射率和相对低电阻率的掺钛氧化锌(ZnO∶Ti)透明导电薄膜,研究了溅射偏压对ZnO∶Ti薄膜结构、形貌和光电性能的影响。结果表明,ZnO∶Ti薄膜为六角纤锌矿多晶结构,具有c轴择优取向。溅射偏压对ZnO∶Ti薄膜的结构和电阻率有重要影响。当溅射偏压为10V时,电阻率具有最小值1.90×10–4?.cm。薄膜具有良好的附着性能,可见光区平均透射率超过90%。该ZnO∶Ti薄膜可以用作薄膜太阳能电池和液晶显示器的透明电极。     

ZnO:Ti透明导电薄膜的制备与光电性能研究

采用直流磁控溅射法,在水冷7059玻璃衬底上制备了具有高透射率和相对低电阻率的掺钛氧化锌(ZnO:Ti)透明导电薄膜,研究了溅射偏压对ZnO:Ti 薄膜结构、形貌和光电性能的影响.结果表明,ZnO:Ti 薄膜为六角纤锌矿多晶结构,具有c轴择优取向.溅射偏压对ZnO:Ti 薄膜的结构和电阻率有重要影响.当溅射偏压为10 V时,电阻率具有最小值1.90×10–4 Ω· cm.薄膜具有良好的附着性能,可见光区平均透射率超过90%.该ZnO:Ti薄膜可以用作薄膜太阳能电池和液晶显示器的透明电极.     

Al-Zr共掺杂ZnO透明导电薄膜制备及光电性能研究

采用直流磁控溅射法,在室温水冷玻璃衬底上制备出Al-Zr共掺杂的ZnO透明导电薄膜。研究结果表明,Ar气压强对Al-Zr共掺杂ZnO透明导电薄膜的结构和电阻率有显著影响。X射线衍射(XRD)表明,Al-Zr共掺杂ZnO透明导电薄膜为六角纤锌矿结构的多晶薄膜,且具有C轴择优取向。扫描电镜(SEM)观察表明,Ar气压强对Al-Zr共掺杂ZnO透明导电薄膜的微观结构影响较大。薄膜的厚度随Ar气压强的增加而变薄,在Ar气压强为2.5Pa时,制备的Al-Zr共掺杂ZnO薄膜电阻率具有最小值1.01×10-3Ω.cm,在可见光区(500～800nm)平均透过率超过93%。     

Highly transparent and conducting zinc oxide films deposited by activated reactive evaporation

Highly transparent and conducting undoped zinc oxide films have been obtained with a best resistivity of ～1.1 × 10^-3 Ω cm, a carrier density of ～1.5 × 10²⁰ cm^?3 and a mobility of ～38 cm²V^{?1s ?1}. These were produced by activated reactive evaporation at a deposition rate of 2 to 8Å/s with a substrate temperature ≤200° C. The films deposited by this process were found to have resistivities that were thickness independent and also were relatively insensitive to deposition parameters. In terms of conductivity, it was found that films deposited at higher temperatures (T > 300°+ C) were always inferior to the films deposited below 200° C. High temperature vacuum annealing (350° C) significantly degraded the resistivity of the undoped films deposited at low temperature; this was attributable to a drop in both the electron concentration and the mobility. Aluminum doping was found to be able to stabilize the electron concentration while the drop in mobility was found to be related to the choice of substrate.     

Influence of the distance between target and substrate on the properties of transparent conducting Al-Zr co-doped zinc oxide thin films

Highly transparent and conducting Al-Zr co-doped zinc oxide (ZAZO) thin films were successfully prepared on glass substrate by direct current (DC) magnetron sputtering at room temperature.The distance between target and substrate was varied from 45 to 70 mm.All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate.The crystallinity increases obviously and the electrical resistivity decreases when the distance betwe...     

Influence of the distance between target and substrate on the properties of transparent conducting Al-Zr co-doped zinc oxide thin films

Highly transparent and conducting AI-Zr co-doped zinc oxide (ZAZO) thin films were successfully prepared on glass substrate by direct current (DC) magnetron sputtering at room temperature. The distance between target and substrate was varied from 45 to 70 mm. All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. The crystallinity increases obviously and the electrical resistivity decreases when the distance between target and substrate decreases from 70 to 50 mm. However, as the distance decreases further, the crystallinity decreases and the electrical resistivity increases. When the distance between target and substrate is 50 mm, it is found that the lowest resistivity is 6.9×10~(-4) Ω·cm.All the deposited films show a high average transmittance of above 92% in the visible range.     

Influence of the distance between target and substrate on the properties of transparent conducting AI-Zr co-doped zinc oxide thin films

Highly transparent and conducting Al-Zr co-doped zinc oxide （ZAZO） thin films were successfully prepared on glass substrate by direct current （DC） magnetron sputtering at room temperature. The distance between target and substrate was varied from 45 to 70 mm. All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. The crystallinity increases obviously and the electrical resistivity decreases when the distance between target and substrate decreases from 70 to 50 mm. However, as the distance decreases further, the crystallinity decreases and the electrical resistivity increases. When the distance between target and substrate is 50 ram, it is found that the lowest resistivity is 6.9 × 10^-4Ω cm. All the deposited films show a high average transmittance of above 92% in the visible range.     

Development of Nano‐TiO2 dye sensitised solar cells on high mobility transparent conducting oxide thin films

The optical transmission of dye‐sensitised solar cells (DSCs) can be tuned by altering the dye and/or particle size of the mesoporous TiO₂ layers, to allow their application as the top device in tandem solar cells. To benefit from this semi‐transparency, parasitic optical losses by the transparent electrodes must be minimised. This work investigates the influence of using two different transparent conductors, namely, the high mobility material titanium doped indium oxide (ITiO) and fluorine doped tin oxide (FTO) as electrodes for semi‐transparent DSCs. The overall NIR transparency through the DSCs increased significantly as each FTO electrode was replaced by an ITiO electrode. This increase was from 20–45% in the 1300–700 nm wavelength range for fully FTO‐based cells, to about 60% for fully ITiO‐based cells, across the same spectrum. DSCs prepared on these electrodes exhibited short circuit currents ranging from 14·0–14·9 mA/cm². The conversion efficiency of the cell with ITiO as both the front and rear electrodes was 5·8%, which though significant, was lower than the 8·2% attained by the cell using FTO electrodes, as a result of a lower fill factor. Improvements in the ITiO thermal stability and in the processing of the TiO₂ interfacial layer are expected to improve the cell efficiency of such single DSC devices. The high current density and optical transparency of ITiO‐based DSCs make them an interesting option for tandem solar cells. Copyright © 2008 John Wiley & Sons, Ltd.     

电子束沉积生长高迁移率IMO透明导电薄膜的研究

研究了利用电子束反应蒸发技术梯度速率生长高迁移率In2O3:Mo(IMO)薄膜的微观结构、光学和电学性能。高纯度In2O3:MoO3陶瓷靶和O2作为源材料。首先,利用低沉积速率(约0.01nm/s)生长一层厚度约为30nm的IMO薄膜,作为缓冲层,其次,提高生长速率至0.04nm/s,高速率生长IMO薄膜,薄膜厚度约50nm。典型薄膜电阻率ρ约为2.5×10-4Ωcm,方块电阻Rs约为22.5Ω,载流子浓度n～5.8×1020cm-3,电子迁移率μ约为47.1cm2V-1s-1,可见光和近红外区域平均透过率约为80%。获得的IMO薄膜光电性能和直接利用低速率生长的薄膜特性相当或更好,并且极大地降低了薄膜生长时间。     

Electrospray deposition and characterization of cobalt oxide thin films

Cobalt oxide thin films were fabricated by means of electrospray deposition. The obtained films were characterized by Raman spectroscopy, X-ray diffraction and Scanning electron microscopy. The solution that was used gave the Co₃O₄ phase at different growth temperatures. The best granular surfaces were obtained at 250 °C as verified by all characterization techniques, while flaky surfaces were obtained at higher temperatures. The surface morphology is mostly granular except for high temperatures where the cobalt oxide is formed as flakes instead of grains.     

直流磁控溅射法制备ZnO:W透明导电薄膜及其性能表征

利用直流磁控溅射法成功地在室温玻璃衬底上制备出了电阻率低、透光率高的掺钨氧化锌（ZnO:W）透明导电薄膜。沉积压强在12-21 Pa之间变化。X射线衍射结果表明实验制备的ZnO:W为六方纤锌矿结构的多晶薄膜,具有垂直于衬底方向的c轴择优取向。沉积压强对ZnO:W薄膜的晶化程度、形貌和电阻率有很大影响,而对其透光率和光学带隙及折射率影响不大。当沉积压强为21 Pa,溅射功率为130 W时,所制备薄膜的电阻率达到最小值1.5×10-4 Ω·cm,其方块电阻、可见光透过率分别为6.8 Ω/□和91.3%。     

Structural and optical characterizations of spin coated cobalt-doped cadmium oxide nanostructured thin films

Cd_1−xCo_xO thin films (with molar ratios x=0.0–8.0%) were grown onto glass substrates via the sol–gel spin coating technique. XRD results indicate that a CdO single phase with a cubic polycrystalline structure is formed. The crystallinity of CdO thin films is gradually deteriorated with increasing the Co ratio. AFM images of the films confirm the decrease of the grain size of the CdO films with increasing Co content. The direct optical band gap is red shifted from 2.580 eV to 2.378 eV with the increase of Co content. The refractive index, the dispersion parameters, and the optical conductivity of CdO thin films showed an enhancement with increasing cobalt dopant ratio. The correlation between the structural modifications and the resultant optical properties are reported.