柔性透明导电薄膜的制备及其发展前景

随着电子器件向小型化和轻便化方向发展,柔性衬底的透明导电薄膜将成为硬质衬底透明导电薄膜的更新换代产品,因此其研究备受关注.综述了柔性透明导电膜的主要制备技术及其优缺点,阐述了当前该领域的最新研究成果及应用,并讨论了工业应用对柔性透明导电膜的性能要求及其未来发展趋势.     

柔性透明导电膜衬底材料的研究进展

综述了柔性透明导电膜材料的应用以及可用作柔性透明导电膜衬底材料的种类、存在的问题和可行的解决方法。介绍了柔性透明导电膜材料的优点、应用和国内外研究现状。重点介绍了可用作柔性透明导电膜衬底的聚合物材料—聚酰亚胺和聚酯,分析了各自的特点。通过分析柔性衬底存在的不足,寻求可行的解决方法,使柔性衬底可以更好地满足导电膜对衬底材料的要求,为柔性衬底材料的设计提供依据。     

低温沉积ITO透明导电膜的研究

通过探讨半导体氧化物ITO膜的透光和导电机理,用反应性直流磁控溅射的镀膜工艺,在有机玻璃上低温镀制(ITO)膜,研究ITO膜溅射工艺参数与透光和导电性能的关系,实现了在低温下镀制(ITO)膜的技术,其透光率≥80%以上,表面电阻≤30Ω/□.     

柔性衬底氧化物半导体透明导电膜的研究进展

回顾和评述了柔性衬底氧化物透明导电膜（包括锡掺杂的三氧化二铟ITO薄膜、铝掺杂的氧化锌AZO薄膜等）的研究进展情况。报道了在柔性衬底上制备的ITO膜、ZnO膜的光电性质对衬底种类、制备工芑及制备参数的依赖关系，给出了在此领域内应进一步进行的工作。     

可用于沉积透明导电氧化物薄膜的柔性衬底研究进展

柔性衬底表面沉积TCO薄膜具有许多独特的优点且应用广泛.但柔性衬底存在不耐高温的缺点,如何选择合适的柔性衬底,在表面沉积TCO薄膜过程中至关重要.简单介绍了各种柔性衬底的相关性能,阐述了当前国内外在该领域中各柔性衬底的研究成果,展望了未来柔性衬底的选择及应用趋势.     

柔性透明导电薄膜及其制备技术

在柔性衬底上制作的器件具有重量轻、柔软等优点,所以柔性透明导电薄膜成为当前的研究热点.柔性衬底存在不耐高温的缺点,从而限制了柔性透明导电薄膜的性能.总结了近年来对柔性衬底材料处理的方法,并介绍了柔性透明导电ITO薄膜和ZAO薄膜,分析了它们的研究现状,同时讨论了柔性薄膜的制备方法,最后对柔性透明TCO领域未来的研究和应用工作进行了展望.     

ITO透明导电玻璃的除霜试验研究

介绍了氧化钢锡（ＩＴＯ）透明导电玻璃的除霜试验结果,并对ＹＦＯ透明导电玻璃应用于汽车挡风玻璃的可能性进行了分析。     

柔性衬底铝掺杂氧化锌透明导电膜的特性研究

室温下采用射频磁控溅射法在有机薄膜－聚丙烯己二酯（polypropylene adipate,PPA)衬底上制备出了ZnO:Al(AZO)透明导电膜。其它制备参数保持不变的条件下通过改变淀积时间得到厚度不同的薄膜，并对不同厚度AZO薄膜的结构特性、光学特性和电学特性进行了研究。     

氧化铟锡(ITO)薄膜的透明吸波特性研究

利用直流磁控溅射技术室温下在柔性聚酯薄膜衬底上制备了ITO薄膜,将ITO薄膜与有机玻璃和空白聚酯薄膜等介质材料组合成复合结构,最终得到吸波能力较强的透明吸波体.该吸波体在Ku带(12～18GHz)范围波段衰减低于-10dB,峰值超过-20dB,且在可见光区透光率达到68%.     

ITO透明导电薄膜的研究进展

介绍了ITO薄膜的基本特性和透明导电原理,综述了ITO薄膜主要的制备技术及其研究进展,并指出了不同制备方法的优缺点.还对ITO薄膜晶格常数畸变、载流子浓度上限和最佳掺杂量、红外反射率、光吸收边的移动等基础理论研究进展进行了归纳.今后,还需要在低温或室温ITO薄膜的制备、ITO薄膜的导电机理、纳米尺度ITO材料的特性等方面加强研究.     

Edge isolation of transparent conductive polymer (TCP) thin films on flexible substrates using UV laser ablation

The purpose of this study was to directly use the writing techniques for the complex electrode edge isolation of transparent conductive polymer (TCP) thin films by a nanosecond pulsed UV laser processing system. The processing parameters including the laser pulse energy, the pulse repetition frequency, and the scan speed of galvanometers were examined to ablate the TCP films deposited on polyethylene terephtalate substrates of 188 microm thick. The thickness of TCP films was approximately 20 nm. The laser pulse repetition frequency and the scan speed of galvanometers were applied to calculate the overlapping rate of laser spots and to discuss the patterning region quality. Surface morphology, edge quality, and width and depth of edge isolated patterning structures after laser ablation process were measured by a three-dimensional confocal laser scanning microscope. In addition, the electrical conductivity of ablated TCP films was measured by a four-point probes instrument. After isolated line patterning was formed, the ablated TCP films with a better edge quality were obtained directly when the overlapping rate of laser spots, the scan speed, and the pulse repetition rate were 83.3%, 200 mm/s, and 40 kHz, respectively. The better surface morphology of electrode pattern structures was also obtained when the scan speed and the pulse repetition rate were 500 mm/s and 40 kHz, respectively.     

New transparent conductive films: FTO coated ITO

New transparent conductive films, fluorine doped tin oxide (FTO) films coated on indium-tin-oxide (ITO) films, were developed. These transparent conductive films were prepared by the spray pyrolysis deposition method at a substrate temperature of 350 °C in ITO and 400 °C in FTO. For ITO deposition, an ethanol solution of indium(III) chloride, InCl₃·4H₂O, and tin(II) chloride, SnCl₂·2H₂O [Sn/(In+Sn), 5 at.%] was sprayed on a Corning #7059 glass substrate (100×100×1.1 mm³). After the deposition, FTO films were consecutively deposited for protecting oxidation of ITO films. FTO deposition was carried out by an ethanol solution of tin(IV) chloride, SnCl₄·5H₂O within the saturated water solution of NH₄F. These new transparent conductive films achieved the lowest resistivity of 1.4×10⁻⁴ Ω cm and the optical transmittance of more than 80% in the visible range of the spectrum. The electrical resistance of these new transparent conductive films increased by less than 10% even when exposed to high temperatures of 300-600 °C for 1 h in the air.     

Preparation and properties of transparent conductive indium-tin-oxide/polyimide substrates via a sol-gel process

High temperature, flexible and colorless indium-tin-oxide (ITO) coated plastic substrates have been prepared from a series of thermally stable, high glass transition temperature (T_g) and colorless copolyimide films. The copolyimides were synthesized from 3,3′-diaminodiphenylsulfone, 9,9′-bis(4-aminophenyl) fluorene and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride monomers. Their T_gs were around 285-365 °C. The conductive ITO was synthesized by a sol-gel method, and then deposited onto the copolyimide films by a spin coating process. After thermal treatment at 300 °C under a nitrogen/hydrogen mixture gas for 24 h, the resistivity of the ITO film was 10⁻³ Ω cm, and its transmittance was 75% at the visible light region. Scanning electron microscopy and X-ray diffraction were used to observe the surface and morphology of the ITO films. UV-visible spectroscopy and the four-probe method were used to study their optical and electrical properties. The high performance ITO/plastic substrates can be used in the next generation flexible flat panel displays and solar cell.     

ITO薄膜的制备以及性能的研究

在室温条件下通过直流磁控溅射法在普通玻璃基体上制备了光电性能优良的ITO薄膜。靶材为ITO陶瓷靶,其中In2O3与SnO2的质量比为9∶1。运用UV-2550紫外可见光光度计测量样品的透光率,采用SZT-2四探针测试仪测量样品表面的电阻率,用扫描电镜(SEM)对样品进行表征。研究了溅射压强、溅射功率等参数对薄膜光电性能的影响。研究表明,ITO薄膜的电阻率随着溅射功率的增大而减小,在溅射功率为110W时ITO薄膜的透光率有相对好的数值。溅射压强为1.0Pa时既能保持ITO薄膜低的电阻率又能保证高的透光率。     

Nanostructuring thin Au films on transparent conductive oxide substrates

Fabrication processes of Au nanostructures on indium-tin-oxide (ITO) surface by simple, versatile, and low-cost bottom-up methodologies are investigated in this work. A first methodology exploits the patterning effects induced by nanosecond laser irradiations on thin Au films deposited on ITO surface. We show that after the laser irradiations, the Au film break-up into nanoclusters whose mean size and surface density are tunable by the laser fluence. A second methodology exploits, instead, the patterning effects of standard furnace thermal processes on the Au film deposited on the ITO. We observe, in this case, a peculiar shape evolution from pre-formed nanoclusters during the Au deposition stage on the ITO, to holed nanostructures (i.e. nanorings), during the furnace annealing processes. The nanorings depth, height, width, and surface density are shown to be tunable by annealing temperature and time.     

Structural, electrical and bending properties of transparent conductive Ga-doped ZnO films on polymer substrates

We investigated the characteristics of highly transparent conductive Ga-doped ZnO (GZO) polycrystalline films of 100 nm thickness deposited on glass and polymer substrates. GZO films were deposited by ion plating with dc-arc discharge. We developed multiple-deposition method to obtain various deposition process temperatures lower than 100 °C. Cross-sectional SEM images show that all the GZO films have columnar structure. Analysis of data obtained by XRD measurements shows that all the GZO films with wurtzite structure exhibit highly (002) orientation perpendicular to the substrate. The resistivity of the GZO films deposited on polyester and glass substrates were 5.0 × 10^-4 Ω · cm. The mechanical bending properties of the GZO films were investigated by comparing the sheet resistance determined before and after a bending test with various bending diameters. For the bending diameter of more than 30 mm, all the GZO films exhibited excellent bending properties with no change in sheet resistance. For the bending diameter of less than 20 mm, we found the sheet resistance affected by the bending. We demonstrated that our multiple-deposition method to achieve different controllable polyester substrate temperatures is highly suitable for improving the bending properties of GZO films.     

Preparation of properties of SWNT/graphene oxide type flexible transparent conductive films

Single walled carbon nanotube (SWNT)/graphene oxide (GO) hybrid films were prepared by a facile bar coating method on a polyethylene terephthalate substrate using a mixed solution of SWCNTs and GO. An acryl type polymer was employed as a dispersion agent to obtain SWCNT and GO suspension in ethyl alcohol. The SWCNT/GO hybrid films were highly transparent and electrically conductive, showing 80% transmittance and 1.8 x 10(3) ohm/sq surface resistance. The surface resistance of the SWCNT/GO film could be further improved to 750 ohm/sq by hydrazine vapor reduction.     

Continuous production of flexible carbon nanotube-based transparent conductive films

This work shows a simple, single-stage, scalable method for the continuous production of high-quality carbon nanotube-polymer transparent conductive films from carbon feedstock. Besides the ease of scalability, a particular advantage of this process is that the concentration of nanotubes in the films, and thus transparency and conductivity, can be adjusted by changing simple process parameters. Therefore, films can be readily prepared for any application desired, ranging from solar cells to flat panel displays. Our best results show a surface resistivity of the order of 300 Ω square^-1 for a film with 80% transparency, which is promising at this early stage of process development.     

Continuous production of flexible carbon nanotube-based transparent conductive films

Abstract

This work shows a simple, single-stage, scalable method for the continuous production of high-quality carbon nanotube-polymer transparent conductive films from carbon feedstock. Besides the ease of scalability, a particular advantage of this process is that the concentration of nanotubes in the films, and thus transparency and conductivity, can be adjusted by changing simple process parameters. Therefore, films can be readily prepared for any application desired, ranging from solar cells to flat panel displays. Our best results show a surface resistivity of the order of 300 Ω square^-1 for a film with 80% transparency, which is promising at this early stage of process development.     

Patterning of ITO films on flexible substrates by using self-assembled monolayer

The patterning of indium tin oxide (ITO) films on flexible polyester (PET) substrates by using a self-assembled monolayer (SAM) of octadecyltrimethoxysilane (OTMS) was investigated. After a SAM is deposited on ITO films, the ITO surface hydrophilicity and electron transfer characteristics are altered. The contact angle and electrochemical cyclic voltammetry analyses indicate the optimal process to form a SAM on ITO films operated in a low-humidity environment at 25 ºC for 24 h. The AFM observation shows that the ITO films covered by a SAM can be protected during etching in an oxalic solution, which means a SAM can well play the role of a photoresist during lithographic process.