Deposition of Indium Tin Oxide Films on Acrylic Substrates by Radiofrequency Magnetron Sputtering

Indium tin oxide (ITO) films were deposited onto acrylic substrates by rf magnetron sputtering. Low substrate temperature (<80°C) and low rf power (<28 W) were maintained during sputtering to prevent acrylic substrate deformation. The influence of sputtering parameters, such as rf power, target-to-substrate distance, and chamber pressure, on the film deposition rate, the electrical properties, as well as the optical properties of the deposited films was investigated. Both the refractive index and the extinction coefficient were derived. The high reflection at wavelengths greater than 3 μ made these sputtered ITO films applicable to infrared mirrors.     

Optimization of the sputtering process parameters of GZO films using the Grey–Taguchi method

This paper examines the optimization of the process parameters of GZO films deposited on polyethylene terephthalate substrates by R.F. magnetron sputtering using the Taguchi method, aiming to obtain highly transparent and conductive films. The influences of the various sputtering factors (R.F. power, sputtering pressure, deposition time, substrate temperature and post-annealing temperature) on electrical resistivity and structural, morphological and optical transmittance of GZO films are analyzed. The electrical resistivity and the optical transmittance of GZO films were improved by post-annealing the substrate during the deposition process. Experimental results indicate the optimal process parameters in GZO films deposited on polyethylene terephthalate substrates can be determined effectively. The electrical resistivity of GZO films is decreased from 1.194 × 10⁻³ Ω cm to 8.627 × 10⁻⁴ Ω cm and the optical transmittance is increased from 86.148% to 90%, leading to multiple performance characteristics in deposition qualities through the Grey–Taguchi method.     

ITO薄膜射频磁控溅射法制备及性能研究

以10%SnO2和90%In2O3(以质量计)烧结成的ITO氧化物陶瓷为靶材,采用射频磁控溅射法在玻璃基片成功地制备出光电性能优异的ITO透明导电薄膜。研究了基片温度和氧分压溅射工艺参数对ITO薄膜的结构和光电性能的影响。实验结果表明,采用氧化铟锡陶瓷靶射频磁控溅射制备的ITO薄膜沿(222)晶面生长,薄膜紫外透射光谱的吸收截止边带随着衬底温度和氧分压的升高向短波长方向漂移。     

Room temperature preparation of high performance AZO films by MF sputtering

Aluminum-doped zinc oxide (AZO) thin films have been deposited by MF magnetron sputtering from a ceramic oxide target without heating the substrates. This study has investigated effects of sputtering power on the structural, electrical and optical properties of the AZO films. The films delivered a hexagonal wurtzite structure with (002) preferential orientation and uniform surface morphology with 27–33 nm grain size. The results indicate that residual stress and grain size of the AZO films are dependent on sputtering power. The minimum resistivity of 7.56×10^?4 Ω cm combined with high transmittance of 83% were obtained at deposited power of 1600 W. The films delivered the advantages of a high deposition rate at low substrate temperature and should be suitable for the fabrication of low-cost transparent conductive oxide layer.     

非晶硅太阳能电池背反ZnO:Al薄膜制备

以ZnO:Al(2%Al2O3,质量分数)为靶材,用射频磁控溅射在玻璃衬底上制备ZnO:Al薄膜,分析了各沉积参数对薄膜光电性能的影响。结果表明:溅射功率对ZnO:Al的透过率影响最大,其次是反应腔室压力,而衬底温度对透过率几乎没有影响。ZnO:Al的电阻率主要取决于衬底温度和溅射功率。综合考虑透过率和电阻率,确定了背反ZnO:Al的最佳沉积参数(衬底温度为200℃,溅射功率为200W,反应腔室压力为0.6Pa),得到了透过率大于85%,电阻率最小为7.6×10-4Ωcm的ZnO:Al薄膜。制备了ZnO:Al/Ag/ss(stainless steel)背反电极,并将其用于非晶硅太阳能电池。与无背反的不锈钢衬底上的电池相比,非晶硅太阳能电池短路电流密度增加了16%。     

Study of a sandwich structure of transparent conducting oxide films prepared by electron beam evaporation at room temperature

ABSTRACT: Transparent conducting ZnO/Ag/ZnO multilayer electrodes having electrical resistance much lower than that of widely used transparent electrodes were prepared by ion-beam-assisted deposition (IAD) under oxygen atmosphere. The optical parameters were optimized by admittance loci analysis to show that the transparent conducting oxide (TCO) film can achieve an average transmittance of 93%. The optimum thickness for high optical transmittance and good electrical conductivity was found to be 11 nm for Ag thin films and 40 nm for ZnO films, based on the admittance diagram. By designing the optical thickness of each ZnO layer and controlling process parameters such as IAD power when fabricating dielectric-metal-dielectric films at room temperature, we can obtain an average transmittance of 90% in the visible region and a bulk resistivity of 5 x 10^-5 ohm-cm. These values suggest that the transparent ZnO/Ag/ZnO electrodes are suitable for use in dye-sensitized solar cells.     

Thin‐film polyimide/indium tin oxide composites for photovoltaic applications

Soluble polyimides were prepared from suitable monomers and were evaluated for their thermal and mechanical properties. The polymers were processed into films for use as supports for transparent, conductive indium tin oxide (ITO) layers. After deposition, annealing in vacuo at temperatures up to 400°C was performed to test the ability of the materials to endure typical device fabrication temperatures without damage to the ITO‐coated polymeric substrate. The evolution of the structural, optical, and electrical characteristics with the annealing temperature was analyzed and compared with that of polymeric and conventional glass substrates as references. Polyimide 6F6F, synthesized from hexafluoroisopropylidene diphthalic dianhydride and hexafluoroisopropylidene dianiline, had optimal characteristics for photovoltaic applications, permitting the achievement of conductive, ITO‐coated samples with optical transmission greater than 75% in the visible and near‐infrared wavelength ranges, without significant deterioration of their properties after vacuum annealing at temperatures up to 350°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3491–3497, 2007     

Sol–Gel‐Derived High‐Performance Stacked Transparent Conductive Oxide Thin Films

Single‐ and multi‐layer transparent conductive oxide (TCO) thin films exhibiting high performance, good packing density and low surface/interface roughness are deposited on silica glass substrates by the sol–gel method. The crystal and microstructural properties of the TCO thin films are evaluated as an alternate to films prepared by ultra‐high vacuum deposition. Tin‐doped indium oxide (ITO) thin films produced using a two‐step drying process showed low surface roughness because of dense packing structure not only horizontal but also vertical directions. As a result, electrical conductivity, carrier concentration, carrier mobility, and optical transmittance of 2.3 × 10³ S/cm, 8 × 10²⁰ cm^?3, 18 cm²/Vs, and over 98% at 500 nm, respectively, were achieved. A multilayer ZnO/ITO stacked structure was also fabricated using the sol–gel process. Our findings suggest that solution‐based methods show promise as an alternative to existing ultra‐high vacuum methods to fabricate TCO thin films.     

Sintering and Electrical Properties of Titania- and Zirconia-Containing ln2O3-Sno2(ITO) Ceramics

The deposition rate and film quality of In₂O₃-SnO₂ (ITO) transparent electrodes processed by sputtering are improved when using dense sputtering targets. Unfortunately, ITO ceramics do not sinter easily. It is shown that addition of TiO₂ (<1 wt%) to ITO greatly increases densification without degrading electrical properties of sputtered films. The influence of ZrO₂ and SiO₂ was also investigated.     

空气和氮气气氛中热处理温度对ITO薄膜性能影响

以InCl_3·4H_2O和SnCl_4·5H_2O为主要原料,采用溶胶-凝胶法和旋转涂膜工艺。在玻璃基片上制备掺锡氧化铟透明导电薄膜(ITO),采用x-射线粉末衍射、紫外-可见透射光谱和四探针技术,研究了在空气和氮气气氛中,不同热处理温度对ITO薄膜的微结构、光学和电学性能的影响。     

Influence of ZnO buffer layer on AZO film properties by radio frequency magnetron sputtering

Transparent conductive films of Al-doped zinc oxide (AZO) were deposited on glass substrates under various ZnO buffer layer deposition conditions (radio frequency (r.f.) power, sputtering pressure, thickness, and annealing) using r.f. magnetron sputtering at room temperature. This work investigates the influence of ZnO buffer layer on structural, electrical, and optical properties of AZO films. The use of grey-based Taguchi method to determine the ZnO buffer layer deposition processing parameters by considering multiple performance characteristics has been reported. Findings show that the ZnO buffer layer improves the optoelectronic performances of AZO films. The AZO films deposited on the 150-nm thick ZnO buffer layer exhibit a very smooth surface with excellent optical properties. Highly c-axis-orientated AZO/ZnO/glass films were grown. Under the optimized ZnO buffer layer deposition conditions, the AZO films show lowest electrical resistivity of 6.75 × 10⁻⁴ Ω cm, about 85% optical transmittance in the visible region, and the best surface roughness of R_a = 0.933 nm.     

Influence of Ag incorporation on the structural,optical and electrical properties of ITO/Ag/ITO multilayers for inorganic all-solid-state electrochromic devices

Indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO, IAI) multilayer structures were prepared by DC magnetron sputtering as a conductive transparent electrode for inorganic all-solid-state electrochromic devices. A thin layer of silver (Ag) with various thicknesses was inserted between two layers of ITO films. The XRD and SEM results revealed that the microscopic morphology of Ag film was closely related to the thickness. Besides, the electrical and optical properties of the IAI multilayers were significantly influenced by the Ag layer thickness. The optimized IAI multilayers demonstrated the best combination of electrical and optical properties with a figure of merit of 54.05 (sheet resistance of 6.14 Ω/cm²and optical transmittance of 90.83%) when the Ag film was 10 nm thick. In order to evaluate the IAI multilayers as a transparent electrode for electrochromic applications, two ECDs with the structures of ITO/NiO_x/LiPON/WO₃/ITO and ITO/NiO_x/LiPON/WO₃/IAI were prepared, and their electro-optical properties were characterized by cyclic voltammetry (CV), chronoamperometry (CA) and spectroscopic measurements. Compared with ECD the pure ITO top electrode (ITO/NiO_x/LiPON/WO₃/ITO), the ECD with the IAI top electrode (ITO/NiO_x/LiPON/WO₃/IAI) presented a slightly smaller optical modulation amplitude, but a faster switching speed. All our findings indicate that the IAI multilayer structure is a promising alternative to the ITO thin film for inorganic all-solid state electrochromic applications.     

Effect of substrate temperature on the structural,electrical, and optical properties of GZO/ZnO films deposited by radio frequency magnetron sputtering

Ga-doped ZnO (GZO)/ZnO bi-layered films were deposited on glass substrates by radio frequency magnetron sputtering at different substrate temperatures of 100, 200 and 300 °C to investigate the effects of substrate temperature on the structural, electrical, and optical properties of the films. Thicknesses of the GZO and ZnO buffer layer were kept constant at 85 and 15 nm by controlling the deposition times.     

Comparative studies of polypropylene nonwoven sputtered with ITO and AZO

In this study, the polypropylene (PP) spunbonded nonwoven materials were used as substrates for depositing transparent nanostructures on the fiber surfaces. Magnetron sputter coating technique was used to deposit tin‐doped indium oxide (ITO) and aluminum‐doped zinc oxide (AZO) films onto the nonwoven substrates. The structures and properties of the deposited ITO and AZO films were investigated and compared using atomic force microscopy, energy‐dispersive X‐ray (EDX), and electrical and optical tests. The observations by atomic force microscopy revealed the formation of functional nanostructures on the fiber surfaces. EDX analyses confirmed the deposition of ITO and AZO functional films on the PP fibers. It was found that ITO had more compact structures on the fiber surface than AZO under the same sputtering conditions. The transmittance analysis revealed that the nonwoven substrates deposited with nanostructural AZO showed better ultraviolet shielding effect than those coated with ITO in the same thickness. The nonwoven materials coated with ITO had lower electrical resistance than those coated with AZO in the same thickness. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Influence of deposition parameters and annealing treatment on the properties of GZO films grown using rf magnetron sputtering

In this study, transparent conductive films of gallium-doped zinc oxide (GZO) are deposited on soda-lime glass substrates, under varied coating conditions (rf power, sputtering pressure, substrate-to-target distance and deposition time), using radio frequency (rf) magnetron sputtering, at room temperature. The effect of the coating parameters on the structural, morphological, electrical and optical properties of GZO films was studied. This study uses a grey-based Taguchi method, to determine the parameters of the coating process for GZO films, by considering multiple performance characteristics. In the confirmation runs, with grey relational analysis, improvements of 14.1% in the deposition rate, 39.81% in electrical resistivity and 1.38% in visible range transmittance were noted. The influence of annealing treatment, in a vacuum, oxygen, and nitrogen gas atmospheres, at temperatures ranging from 130 to 190 °C, for a period of 1 h, was also investigated. GZO films annealed at 190 °C, in a vacuum, showed the lowest electrical resistivity, at 1.07 × 10⁻³ Ω-cm, with about 85% optical transmittance, in the visible region. It is likely that films grown at lower temperatures (190 °C) could be coated onto polymeric substrates, to produce flexible optoelectronic devices.     

Tubular Sn-filled carbon nanostructures on ITO: Nanocomposite material for multiple applications

Hollow carbon nanostructures filled by metallic Sn were fabricated by means of chemical vapor deposition on transparent Indium Tin Oxide (ITO). We found no need for catalytic particles, and the growth happens in the temperature range 820–940 K. Upon annealing in an oxygen atmosphere, the carbon skin could be burned out, leaving SnO_x pillars on the ITO substrate. The electrical and optical properties of the grown Sn/C and SnO_x nanopillars were characterized.This growth strategy is versatile and can suitably be adapted to different substrate materials, provided that ITO can be deposited and annealed at the temperature required for the formation of the nanostructures. The rational control of this simple growth process and the lack of deposited external catalysts allow the fabrication of ordered, possibly, vertically aligned nanopillars over large areas, with tunable morphological, electrical and optical characteristics. This approach is envisaged as a promising path to develop energy generation and storage electrodes or chemical sensors with improved efficiency.     

Deposition of F-doped ZnO transparent thin films using ZnF2-doped ZnO target under different sputtering substrate temperatures

Highly transparent and conducting fluorine-doped ZnO (FZO) thin films were deposited onto glass substrates by radio-frequency (RF) magnetron sputtering, using 1.5 wt% zinc fluoride (ZnF₂)-doped ZnO as sputtering target. Structural, electrical, and optical properties of the FZO thin films were investigated as a function of substrate temperature ranging from room temperature (RT) to 300°C. The cross-sectional scanning electron microscopy (SEM) observation and X-ray diffraction analyses showed that the FZO thin films were of polycrystalline nature with a preferential growth along (002) plane perpendicular to the surface of the glass substrate. Secondary ion mass spectrometry (SIMS) analyses of the FZO thin films showed that there was incorporation of F atoms in the FZO thin films, even if the substrate temperature was 300°C. Finally, the effect of substrate temperature on the transmittance ratio, optical energy gap, Hall mobility, carrier concentration, and resistivity of the FZO thin films was also investigated.     

Robustification of ITO nanolayer by surface‐functionalization of transparent biopolyimide substrates

Robust and transparent electrodes with good flexibility and high mechanical strength are required for preparing next‐generation electronic devices. Indium tin oxide (ITO) nanolayers have been grown by radio‐frequency sputtering process on reactive surface of transparent and thermostable biopolyimide, derived from an exotic aromatic amino acid, 4‐aminocinnamic acid (4ACA). It is observed that greater surface hydrophilicity of the biopolyimide induces stronger interfacial interaction with ITO nanolayer resulting in smoother surface of the bionanohybrids. Spectroscopy, microscopy, and X‐ray diffraction reveal the successful deposition of the ultra‐thin ITO nanolayer onto the surface‐engineered biopolyimide. The process provides transparent bionanohybrid films with robustness against mechanical deformation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46709.     

Comparative study of sol–gel derived tin-doped indium- and aluminum-doped zinc-oxide coatings for electrical conducting and low-emitting surfaces

Cost-efficient transparent conductive oxide (TCO) compounds based on doped zinc oxide (e.g. aluminum zinc oxide – AZO) have been investigated in addition to the well-established functional coatings of doped indium oxide (e.g. indium tin oxide – ITO). The electrical, morphological and optical properties of both types of coatings are compared. For the deposition of transparent conductive oxides, such as tin-doped indium oxide and aluminum-doped zinc oxide on soda-lime glass, enhanced sol–gel processes have been used. Colloidal solutions consisting of inorganic precursors were applied via dip-coating technique, crystallized on the substrate and subsequently annealed in a reducing atmosphere in order to enrich the number of free charge carriers and the electrical conductivity, respectively. In addition to the conventional layer properties like high transparency in the visible spectral region, this work mainly focuses on the comparison of the infrared-optical characteristics in the mid and far infrared spectral range. The directional-hemispherical reflectance and transmittance of functional ITO and AZO multilayer structures with thicknesses of 50–500 nm were measured in the wavelength range between 0.25 and 35 μm and the thermal emission at ambient temperature was calculated and correlated with the electrical layer properties and the doping level of the coatings. To gain further insights, important characteristics of the coatings, such as layer thickness, surface smoothness, electrical conductivity, doping level, band gap energy as well as the position of the plasma wavelength were analyzed using UV–VIS- and IR-spectroscopy, SEM-, EDX-, XRD- and 4-point conductivity measurements. Both types of the functional coatings are highly transparent in the visible spectral region with over 80% and their specific resistivity reaches values up to 3 × 10⁻⁴ Ω cm. By applying multilayered coatings on soda-lime glass, the surface emittance was reduced from 89% to less than 20% in the infrared spectral range.     

磁控溅射法制备纳米Cu薄膜及其微结构的研究

采用磁控溅射法制备出以ITO为基底的纯Cu薄膜,考察溅射时间和基底温度等工艺条件对生长Cu薄膜的影响.用电子扫描显微镜(SEM)、X射线衍射仪(XRD)对薄膜的形貌、厚度和结构进行表征.实验结果表明:在一定范围内调控衬底温度和溅射时间,可获得不同形貌、尺寸和厚度的Cu薄膜,所得薄膜的晶体结构为面心立方结构,均沿(111...