等离子体辅助ITO薄膜低温生长

采用基片加热和后期热处理的手段使ITO薄膜结晶和调整其组织结构来降低电阻的方法,已经被广泛应用于在玻璃等基体上制备ITO薄膜.但是随着不耐高温的柔性基体的广泛使用,ITO薄膜低温生长已经成为一个重要的研究课题.为此,本研究探讨室温等离子体辅助条件下,ITO薄膜沉积生长过程,以期为上述问题的解决提供理论依据.研究结果表明等离子辅助可以有效控制ITO薄膜的结晶程度和晶粒尺寸以及晶界结构,在优化条件下,在PET基体上制备出电阻率为1.1×10-3Ω·cm的ITO薄膜.     

液晶光阀用ZnSSe薄膜的光电特性研究

用分子束外延法(MBE),在铟锡氧化物(ITO)导电玻璃衬底上生长了ZnSSe薄膜,详细研究了薄膜的光电特性.通过控制反应时的生长参数,制备出了符合紫外液晶光阀设计要求的光导层薄膜.室温下,该薄膜光谱响应截止边的响应度为0.01A/W,紫外/可见光响应对比度大于103.薄膜的暗电阻率随薄膜晶粒增大而减小,在衬底温度为2900C时,所获得的ZnSSe薄膜具有4.3×1011Ω@cm的暗电阻率.频率从40Hz到4000Hz的交流特性测试,也证实该薄膜符合器件紫外成像的工作要求.     

磁控溅射制备ITO薄膜光电性能的研究

采用直流磁控溅射方法在玻璃基底上制备了ITO薄膜.分别用分光光度计和四探针仪测试了所制备ITO薄膜在可见光区域内的透过率和电阻率,研究了溅射气压、氧氩流量比和溅射功率三个工艺参数对ITO薄膜光电性能的影响.研究结果表明,制备ITO薄膜的最佳工艺参数为:溅射气压0.6 Pa,氧氩流量比1:40,溅射功率108 W.采用此工艺参数制备的ITO薄膜在可见光区平均透过率为81.18％,薄膜电阻率为8.9197×10-3Ω·cm.     

ITO薄膜直流反应磁控溅射制备及性能研究

以90wt%In和10wt%Sn铟锡合金为靶材,采用直流磁控反应溅射法在玻璃基片制备ITO透明导电薄膜.用紫外-可见光分光光度计、四探针电阻仪、XRD和SEM分别测试了ITO薄膜的紫外-可见光透射光谱、方块电阻、薄膜的结构和表面形貌.研究了氧分压对ITO薄膜性能的影响.实验结果表明,ITO薄膜随着氧分压的增加,薄膜紫外透射光谱的吸收截止边带向短波长方向漂移.随着氧分压的增大,ITO薄膜的方块电阻增加,结晶程度变好,晶粒尺寸变大.     

柔性PET衬底上低温制备TZO透明导电薄膜

利用直流磁控溅射法,在室温水冷柔性PET衬底上成功制备出了掺钛氧化锌透明导电薄膜(TZO)。通过X射线衍射和扫描电镜等表征方法对薄膜结构和特性进行测试分析,研究了靶与衬底之间的距离(靶基距)对TZO薄膜表面形貌、结构、力学、电学和光学性能的影响。结果表明,实验制备的柔性TZO透明导电薄膜为具有c轴择优取向的六角纤锌矿结构的多晶薄膜;靶基距对PET衬底上的柔性TZO薄膜的性能有较大的影响。随着靶基距从42 mm增大到70 mm,薄膜的生长速率由22.46 nm/min降低到6.92 nm/min;薄膜的电阻率先由55.99×10-4Ω.cm快速减小到5.34×10-4Ω.cm后略有增大并趋稳,5.34×10-4Ω.cm为最小电阻率,其靶基距为52 mm;70 mm靶基距时样品薄膜应力最小,为0.4914 GPa;所有样品的可见光区平均透过率都高于90.97%。     

溅射功率和氧分压对ITO薄膜光电性能的影响研究

采用直流反应磁控溅射法制备了氧化铟锡(ITO)透明导电薄膜,通过四探针、紫外可见分光光度计、X射线衍射(XRD)、霍尔效应仪、扫描电镜(SEM)等对薄膜样品进行了表征,研究了溅射功率和氧分压对ITO薄膜微观结构和光电性能的影响,结果表明:溅射功率对ITO的光电性能影响较小,沉积速率随着溅射功率的增大而加快;随着氧分压的升高,载流子浓度降低,霍尔迁移率先增大后减小,电阻率逐渐增大。在优化的工艺条件下,制备了在可见光区平均透过率达85%、电阻率为1×10-4Ω.cm的光电性能优良的ITO薄膜。     

基于银纳米颗粒墨水在柔性基材表面制备导电薄膜及其电阻率

通过两相界面反应制备出小尺寸银纳米颗粒,用喷墨打印技术和热处理工艺在柔性PET基材表面制备导电薄膜。用紫外-可见光吸收光谱、透射电镜和能谱研究了银颗粒粒径、微结构和成分,结果表明所合成的颗粒为多晶结构,粒径为2～5nm。用扫描电镜和四探针薄膜电阻率测量法研究了热处理温度、时间与薄膜形貌、电阻率之间的关系,结果表明柔性PET塑料表面的银颗粒在150℃条件下处理30min,可获得表面平整、无明显裂纹、电阻率～6.4μΩ.cm的导电薄膜。     

射频溅射功率对室温沉积AZO薄膜性能的影响

本文采用直流射频耦合磁控溅射技术,在玻璃基底上室温沉积AZO薄膜,将射频电源功率从0W增加到到200W。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、紫外分光光度计、霍尔效应测试系统重点研究了AZO薄膜的晶体结构、表面形貌、光学性能和电学性能。研究结果表明,直流射频耦合磁控溅射可以在室温下制备性能优异的AZO薄膜,且射频溅射功率对AZO薄膜光电性能有显著的影响,随着射频功率的提高,AZO薄膜致密性增加,粒子逐渐变大,薄膜表面形貌和生长形态发生一定变化。在射频功率为200W时,室温制备的AZO薄膜电阻率达到最低5.39×10~(-4)Ω·cm,薄膜平均可见光透过率达到82.6%。     

磁控溅射低温沉积ITO薄膜及其光电特性研究

采用直流反应磁控溅射法低温沉积ITO薄膜,用XRD、SEM和UV—Vis分别表征ITO薄膜的晶体结构、表面形貌及其紫外-可见光吸收谱,研究了氧分压、溅射功率及薄膜厚度等工艺参数对薄膜光电性能的影响,结果表明,氧分压过大时,ITO薄膜中有大量的位错和缺陷,使薄膜的电阻率变大,导电性变差;氧分压过小时,薄膜中将有大量氧空位产生,导致晶格变形,使电阻率增加。随着溅射功率增大,在相同时间内薄膜厚度增加,方块电阻减小,薄膜电阻率降低。随着薄膜厚度增加,制备的薄膜晶体结构相对完整,载流子浓度和迁移率逐渐增大,薄膜电阻率变小,进而对样品的光电性能产生明显影响。     

晶粒尺寸对CVD金刚石膜电学特性的影响

通过改变生长参数,采用热丝化学气相沉积(HFCVD)法制备了从10μm到90nm四种晶粒尺寸的金刚石膜,并制作了三明治结构的光电导探测器.采用原子力显微镜和拉曼光谱仪研究了薄膜的结构和表面形貌:表面粗糙度从423nm变化到15nm;晶粒越大,金刚石膜的质量越好.I-V特性测试结果表明随着晶粒尺寸的减小,金刚石膜的电阻率从1011Ω·cm减小到106Ω·cm.在5.9 keV的55Fe X射线辐照下,随着晶粒尺寸的减小,探测器的信噪比(SNR)呈减小趋势.     

Properties of indium tin oxide thin films prepared on the oxygen plasma-treated polycarbonate substrate

We prepared the indium tin oxide thin (ITO) film on the polymer substrate by using facing target sputtering method. To obtain a smooth surface of the ITO thin film for application of OLEDs, before deposition of the ITO thin film, the polymer substrate was given plasma surface treatment. The electrical and surface properties were measured by a Hall Effect measurement and a contact angle measurement. The structural and optical properties were evaluated by an X-ray diffractometer, an atomic force microscope and a UV/VIS spectrometer, respectively. All ITO thin films deposited on plasma-treated polymer substrate showed an average transmittance over 85% in visible range, and the lowest resistivity was 4.17 × 10^− 4 Ω cm.     

Inkjet-printing of indium tin oxide (ITO) films for transparent conducting electrodes

Indium-tin-oxide (ITO) films have been prepared by inkjet-printing using ITO nanoparticle inks. The electrical and optical properties of the ITO films were investigated in order to understand the effects of annealing temperatures under microwave. The decrease in the sheet resistance and resistivity of the inkjet-printed ITO films was observed as the annealing temperature increases. The film annealed at 400 °C showed the sheet resistance of 517 Ω/sq with the film thickness of ∼580 nm. The optical transmittance of the films remained constant regardless of their annealing temperatures. In order to further reduce the sheet resistance of the films, Ag-grid was printed in between two layers of inkjet-printed ITO. With 3 mm Ag-grid line-to-line pitch, the Ag-grid inserted ITO film has the sheet resistance of 3.4 Ω/sq and the transmittance of 84% after annealing at 200 °C under microwave.     

Effect of sputtering power and annealing temperature on the properties of indium tin oxide thin films prepared from radio frequency sputtering using powder target

Indium tin oxide (ITO) thin films were deposited on quartz substrates by radio frequency (RF) sputtering with different RF power (100–250 W) using the powder target at room temperature. The effect of sputtering power on their structural, electrical and optical properties was systematically investigated. The intensity of (400) orientation clearly increases with the sputtering power increases, although the films have (222) preferred orientation. Increasing sputtering power is benefit for lower resistivity and transmittance. The films were annealed at different temperature (500–800 °C), then we explored the relationship between their electro-optical and structural properties and temperature. It has been observed that the annealed films tend to have (400) orientation and then show the lower resistivity and transmittance. The ITO thin film prepared by RF sputtering using powder target at 700 °C annealing temperature and 200 W sputtering power has the resistivity of 2.08 × 10^?4 Ω cm and the transmittance of 83.2 %, which specializes for the transparent conductive layers.     

Effects of substrate temperature on tin-doped indium oxide films deposited by dc arc discharge ion plating

Indium tin oxide (ITO) films were deposited on glass substrate at temperatures ranging from room temperature to 120 °C by the dc arc discharge ion plating technique. The electrical properties and crystallinity of ITO films were investigated. The resistivity of ITO films decreased with the increase of the substrate temperature in deposition, mostly due to increase in Hall mobility above 90 °C. The resistivity of ITO film obtained at temperature 120 °C was 1.33×10⁻⁴ Ω cm. The ITO films crystallized at the substrate temperature higher than 90 °C and the grain size estimated from the (2 2 2) peak in the direction parallel to the surface of the substrate became large with the increase of the substrate temperature. That the Hall mobility increased with the increase of the substrate temperature was speculated to be due to the increase of the grain size in the direction parallel to the surface.     

Effects of heat treatment on properties of ITO films prepared by rf magnetron sputtering

Indium tin oxide (ITO) films were deposited on glass substrates by rf magnetron sputtering using a ceramic target (In₂O₃-SnO₂, 90-10 wt%) without extra heating. The post annealing was done in air and in vacuum, respectively. The effects of annealing on the structure, surface morphology, optical and electrical properties of the ITO films were studied. The results show that the increase of the annealing temperature improves the crystallinity of the films, increases the surface roughness, and improves the optical and electrical properties. The transmittance of the films in visible region is increased over 90% after the annealing process in air or in vacuum. The resistivity of the films deposited is about 8.125×10⁻⁴ Ω cm and falls down to 2.34×10⁻⁴ Ω cm as the annealing temperature is increased to 500°C in vacuum. Compared with the results of the ITO films annealed in air, the properties of the films annealed in vacuum is better.     

Low temperature deposition of ITO on organic films by using negative ion assisted dual magnetron sputtering system

In a magnetron sputter type negative metal ion deposition, the influence of positive bias voltage (V_b) on the surface morphology, electrical resistivity, optical transmittance, and microhardness of ITO prepared on organic polycarbonate films has been investigated. In this study, the V_b increased from 0 to 250 V to attract secondary negative In and Sn metal ions, which were produced from ITO target by surface negative ionization with intense Cs ion bombardments. During deposition although reactive oxygen gas was not introduced into the chamber, by adjusting V_b at 100 V, ITO films on polycarbonate substrate with resistivity as low as 6.1×10⁻⁴ Ω cm and transmittance over 90% at 550 nm have been obtained without intentional substrate heating.AFM measurement also shows that surface roughness varied significantly with V_b. However, too intense ion bombardment originated by high V_b (>100 V) condition increased surface roughness and as a result deteriorated the electrical and optical property of ITO films.     

Structural, electrical and optical properties of ITO films with a thin TiO2 seed layer prepared by RF magnetron sputtering

Tin-doped indium oxide (ITO) films were deposited by RF magnetron sputtering on TiO₂-coated glass substrates (the TiO₂ layer is usually called seed layer). The properties of ITO films prepared at a substrate temperature of 300 °C on bare and TiO₂-coated glass substrates have been analyzed by using X-ray diffraction, atomic force microscope, optical and electrical measurements. Comparing with single layer ITO film, the ITO film with a TiO₂ seed layer of 2 nm has a remarkable 41.2% decrease in resistivity and similar optical transmittance. The glass/TiO₂ (2 nm)/ITO film achieved shows a resistivity of 3.37 × 10⁻⁴ Ω cm and an average transmittance of 93.1% in the visible range. The glass/TiO₂ may be a better substrate compared with bare glass for depositing high quality ITO films.     

Comparative study of ITO and FTO thin films grown by spray pyrolysis

Tin doped indium oxide (ITO) and fluorine doped tin oxide (FTO) thin films have been prepared by one step spray pyrolysis. Both film types grown at 400 °C present a single phase, ITO has cubic structure and preferred orientation (4 0 0) while FTO exhibits a tetragonal structure. Scanning electron micrographs showed homogeneous surfaces with average grain size around 257 and 190 nm for ITO and FTO respectively.The optical properties have been studied in several ITO and FTO samples by transmittance and reflectance measurements. The transmittance in the visible zone is higher in ITO than in FTO layers with a comparable thickness, while the reflectance in the infrared zone is higher in FTO in comparison with ITO. The best electrical resistivity values, deduced from optical measurements, were 8 × 10⁻⁴ and 6 × 10⁻⁴ Ω cm for ITO (6% of Sn) and FTO (2.5% of F) respectively. The figure of merit reached a maximum value of 2.15 × 10⁻³ Ω⁻¹ for ITO higher than 0.55 × 10⁻³ Ω⁻¹ for FTO.     

Investigation of structural properties of ITO thin films deposited on different substrates

The influence of the substrate nature on the structure and morphology of ITO thin films grown by thermal evaporation in vacuum is investigated. The as-prepared metal films with Sn/In molar ratio of 0.1 were subsequently annealed for 2 h at 723 K in air (to obtain tin doped indium oxide), then annealed in vacuum at 523 K, followed by UV irradiation (to reduce the electrical resistivity). Irrespective of substrate nature, XRD data evidence a (222) preferential orientation in films. Substrate nature, annealing in vacuum and UV irradiation influence the structure, morphology, optical, electrical and surface wetting properties of the films' surface.     

Fabrication of transparent conductive films with a sandwich structure composed of ITO/Cu/ITO

New transparent conductive films that had a sandwich structure composed of ITO/Cu/ITO multilayer films were prepared by a conventional RF and DC magnetron sputtering process on a polycarbonate substrate without intentional substrate heating. The thickness of each layer in the ITO/Cu/ITO films was kept constant at 50 nm/5 nm/45 nm. The optoelectrical and structural properties of the films were compared with conventional ITO single-layer films and ITO/Cu/ITO multilayered films. Although both films had identical thickness, 100 nm, the ITO/Cu/ITO films showed a lower resistivity, 3.5 × 10⁻⁴ Ω cm. In optical transmittance measurements, however, the ITO single-layer films showed a higher transmittance of 74% in the wavelength range of 300-800 nm. XRD spectra showed that both the ITO and ITO/Cu/ITO films were amorphous. The figure of merit, φ_TC, reached a maximum of 5.2 × 10⁻⁴ Ω⁻¹ for the ITO/Cu/ITO films, which was higher than the φ_TC of the ITO films (1.6 × 10⁻⁴ Ω⁻¹). The φ_TC results suggested that ITO/Cu/ITO films had better optoelectrical properties than conventional ITO single-layer films.