Electrical and optical properties of indium tin oxide/epoxy composite film

The electrical and optical properties of the indium tin oxide （ITO）/epoxy composite exhibit dramatic variations as functions of the ITO composition and ITO particle size. Sharp increases in the conductivity in the vicinity of a critical volume fraction have been found within the framework of percolation theory. A conductive and insulating transition model is extracted by the ITO particle network in the SEM image, and verified by the resistivity dependence on the temperature. The dependence of the optical transmittance on the particle size was studied. Further decreasing the ITO particle size could further improve the percolation threshold and light transparency of the composite film.

Preparation of High Quality Indium Tin Oxide Film on a Microbial Cellulose Membrane Using Radio Frequency Magnetron Sputtering

微生物引起的纤维素(MC ) 膜由醋菌属 xylinum NUST4.1 生产了，为透明的铟锡氧化物(ITO ) 的制造被用作灵活底层电极。透明、传导性的 ITO 薄电影在房间温度使用收音机频率(RF ) 磁控管劈啪作响在 MC 膜上被扔。最佳 ITO 免职条件被检验水晶的结构，有 X 光检查衍射(XRD ) 的表面形态学和 optoelectrical 特征，扫描电子显微镜学(SEM ) ，原子力量显微镜学(AFM ) ，和紫外光谱学完成。样品的表抵抗与一根四点的探针被测量，这部电影的抵抗力是计算的。结果表明扔的 ITO 晶体的比较喜欢的取向强烈依赖于与氧内容(O2/Ar，体积比率) 在劈啪作响的房间。并且 ITO 水晶的结构直接决定扔 ITO 的电影的传导性。高传导性[pBAD33 上的 PBAD 的表抵抗 120 ntrol，能生产 CoQ10 直到 3.24 mg？

Temperature-dependent bias-stress-induced electrical instability of amorphous indium-gallium-zinc-oxide thin-film transistors

The time and temperature dependence of threshold voltage shift under positive-bias stress（PBS） and the following recovery process are investigated in amorphous indium-gallium-zinc-oxide（a-IGZO） thin-film transistors. It is found that the time dependence of threshold voltage shift can be well described by a stretched exponential equation in which the time constant τ is found to be temperature dependent. Based on Arrhenius plots, an average effective energy barrier Eτ stress= 0.72 eV for the PBS process and an average effective energy barrier Eτ recovery= 0.58 eV for the recovery process are extracted respectively. A charge trapping/detrapping model is used to explain the threshold voltage shift in both the PBS and the recovery process. The influence of gate bias stress on transistor performance is one of the most critical issues for practical device development.

Low Temperature DC Sputtering Deposition on Indium-Tin Oxide Film and Its Application to Inverted Top-emitting Organic Light-emitting Diodes

Indium tin oxide （ITO） ultrathin films were prepared on glass substrate by DC （direct current） magnetron sputtering technique with the assistance of H2O vapor to avoid potential surface damage. The film properties were characterized by X-ray diffraction （XRD） technique, four-point probe method and spectrophotometer. The results show that the deposited ITO film with introduced H2O during sputtering process was almost amorphous. The average visible light transmission of 100 nm ITO film was around 85% and square resistivity was below 80 Ω/square. The film was used as the transparent anode to fabricate an inverted top-emitting organic light-emitting diodes （IT-OLEDs） with the structure of glass substrate/Alq3 （40 nm）/NPB （15 nm）/CuPc （x nm）/ITO anode （100 nm）, where the film thickness of CuPc was optimized. It was found that the luminance of this IT-OLEDs was improved from 25 cd/m^2 to more than 527 cd/m^2 by increasing the thickness of CuPc, and luminance efficiency of 0.24 lm/W at 100 cd/m^2 was obtained, which indicated that the optimized thickness of CuPc layer was around 15 nm.

Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

Indium doped zinc oxide （ZnO：In） thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO：In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82 × 10^-3 Ω. cm and particle grains. The doublelayers structure is designed to fabricate the ZnO：In thin film with low resistivity （2.58 × 10^-3 Ω. cm） and good surface morphology. It is found that the surface morphology of the double-layer ZnO：In film strongly depends on the substratelayer, and the second-layer plays a large part in the resistivity of the doublewlayer ZnO：In thin film. Both total and direct transmittances of the double-layer ZnO：In film are above 80% in the visible light region. Single junction a-Si：H solar cell based on the double-layer ZnO：In as front electrode is also investigated.

Low-Frequency Noise in Amorphous Indium Zinc Oxide Thin Film Transistors with Aluminum Oxide Gate Insulator

Low-frequency noise（LFN） in all operation regions of amorphous indium zinc oxide（a-IZO） thin film transistors（TFTs） with an aluminum oxide gate insulator is investigated. Based on the LFN measured results, we extract the distribution of localized states in the band gap and the spatial distribution of border traps in the gate dielectric,and study the dependence of measured noise on the characteristic temperature of localized states for a-IZO TFTs with Al2 O3 gate dielectric. Further study on the LFN measured results shows that the gate voltage dependent noise data closely obey the mobility fluctuation model, and the average Hooge＇s parameter is about 1.18×10^-3.Considering the relationship between the free carrier number and the field effect mobility, we simulate the LFN using the △N-△μ model, and the total trap density near the IZO/oxide interface is about 1.23×10^18 cm^-3eV^-1.

Sulphurization of the Electrochemically Deposited Indium Sulphide Oxide Thin Film and Its Photovoltaic Applications

The post-deposition heat treatment (annealing) for the electrochemically deposited thin film is often necessary in order to improve its crystallinity. In the present study, the electrochemically deposited indium sulfide oxide thin film was annealed in sulphure atmosphere for 60 min at 150℃ and 300℃. The impact of the annealing process on the composition, crystal structure, and surface morphology of the thin film was investigated. In addition, superstrate heterojunction solar cells based on the annealed film as a buffer layer and tin sulphide as an active layer were fabricated and characterized. They showed diode-like behavior under dark condition and a relatively small photovoltaic effect under AM1.5 illumination condition.

Contact resistance asymmetry of amorphous indium–gallium–zinc–oxide thin-film transistors by scanning Kelvin probe microscopy

In this work, a method based on scanning Kelvin probe microscopy is proposed to separately extract source/drain（S/D） series resistance in operating amorphous indium–gallium–zinc–oxide（a-IGZO） thin-film transistors. The asymmetry behavior of S/D contact resistance is deduced and the underlying physics is discussed. The present results suggest that the asymmetry of S/D contact resistance is caused by the difference in bias conditions of the Schottky-like junction at the contact interface induced by the parasitic reaction between contact metal and a-IGZO. The overall contact resistance should be determined by both the bulk channel resistance of the contact region and the interface properties of the metalsemiconductor junction.

Preparation of indium tin oxide targets with a high density and single phase structure by normal pressure sintering process

The present work mainly describes the technology for preparing indium-tin oxide （ITO） targets by cold isostatic pressing （CIP） and normal pressure sintering process. ITO powders were produced by chemical co-precipitation and shaped into an ITO green compact with a relative density of 60% by CIP under 300 MPa. Then, an ITO target with a relative density larger than 99.6% was obtained by sintering this green compact at 1550℃ for 8 h. The effects of forming pressure, sintering temperature and sintering time on the density of the target were inves- tigated. Also, a discussion was made on the sintering atmosphere.

High-throughput fabrication and semi-automated characterization of oxide thin film transistors

High throughput experimental methods are known to accelerate the rate of research,development,and deployment of electronic materials.For example,thin films with lateral gradients in composition,thickness,or other parameters have been used alongside spatially-resolved characterization to assess how various physical factors affect the material properties under varying measurement conditions.Similarly,multi-layer electronic devices that contain such graded thin films as one or more of their layers can also be characterized spatially in order to optimize the performance.In this work,we apply these high throughput experimental methods to thin film transistors(TFTs),demonstrating combinatorial channel layer growth,device fabrication,and semi-automated characterization using sputtered oxide TFTs as a case study.We show that both extrinsic and intrinsic types of device gradients can be generated in a TFT library,such as channel thickness and length,channel cation compositions,and oxygen atmosphere during deposition.We also present a semi-automated method to measure the 44 devices fabricated on a 50 mm×50 mm substrate that can help to identify properly functioning TFTs in the library and finish the measurement in a short time.Finally,we propose a fully automated characterization system for similar TFT libraries,which can be coupled with high throughput data analysis.These results demonstrate that high throughput methods can accelerate the investigation of TFTs and other electronic devices.

Positive gate bias stress-induced hump-effect in elevated-metal metal-oxide thin film transistors

Under the action of a positive gate bias stress, a hump in the subthreshold region of the transfer characteristic is observed for the amorphous indium-gallium-zinc oxide thin film transistor, which adopts an elevated-metal metal-oxide structure. As stress time goes by, both the on-state current and the hump shift towards the negative gate-voltage direction. The humps occur at almost the same current levels for devices with different channel widths, which is attributed to the parasitic transistors located at the channel width edges. Therefore, we propose that the positive charges trapped at the back-channel interface cause the negative shift, and the origin of the hump is considered as being due to more positive charges trapped at the edges along the channel width direction. On the other hand, the hump-effect becomes more significant in a short channel device （L=2 μm）. It is proposed that the diffusion of oxygen vacancies takes place from the high concentration source/drain region to the intrinsic channel region.

Effect of surfactants on the structure and photoelectric properties of ITO films by sol-gel method

The Indium tin oxide（ITO） thin film possesses excellent photoelectric properties that enable it to act as an ideal transparent conductor.To obtain high-quality ITO films through sol-gel method, the ionic surfactant monoethanolamine and the non-ionic surfactant polyethylene glycol（PEG） were added to the ITO precursor slurry.The influences of surfactants on the structural and photoelectric properties of ITO film samples were investigated.XRD patterns indicated that surfactant monoethanolamine contributed to film predominant grain orientation along the（400） plane.The high transmittance（over 95%） was attributed to the preferred orientation and the grain size expansion of ITO films.SEM showed that the surface particle size and the morphology of ITO films were strongly dependent on the kind of surfactants used.Moving to the shortwave region, the absorption edge of the films exhibited the Burstein-Moss shift.

模压成型压力对氧化铟锡(ITO)靶材性能影响研究

以化学共沉淀-煅烧法制备的纳米ITO粉体为原料,通过模压、冷等静压成型,采用常压烧结法制备了ITO靶材,研究了模压成型压力对ITO靶材相对密度、电阻率和晶粒尺寸的影响。结果表明,模压成型压力60 MPa且烧结条件适宜时,制得的ITO靶材相对密度为99.81%、电阻率为1.707×10^(-4)Ω·cm、平均晶粒尺寸为7.62μm。研究结果可为ITO靶材的致密化与大型化生产提供借鉴。

Influence of Annealing Temperature on the Microstructure and Electrical Properties of Indium Tin Oxide Thin Films

Indium tin oxide （ITO） thin films were prepared on alumina ceramic substrates by radio frequency magnetron sputtering. The samples were subsequently annealed in air at temperatures ranging from 500 to 1,100 ℃ for 1 h. The influences of the annealing temperature on the microstructure and electrical properties of the ITO thin films were investigated, and the results indicate that the as-deposited ITO thin films are amorphous in nature. All samples were crystallized by annealing at 500 ~C. As the annealing temperature increases, the predominant orientation shifts from （222） to （400）. The carrier concentration decreases initially and then increases when the annealing temperature rises beyond 1,000 ℃. The resistivity of the ITO thin films increases smoothly as the annealing temperature increases to just below 900 ℃. Beyond 900 ℃, however, the resistivity of the films increases sharply. The annealing temperature has a significant effect on the stability of the ITO/Pt thin film thermocouples （TFTCs）. TFTCs annealed at 1,000 ℃ show improved high- temperature stability and Seebeck coefficients of up to 77.73 pV/℃.

Threshold voltage tuning and printed complementary transistors and inverters based on thin films of carbon nanotubes and indium zinc oxide

碳 nanotubes CNT 为打印 macroelectronics 作为重要材料出现了。因为它仍然正在质问使可靠 n 类型成为 CNT 晶体管，然而，完全基于 CNT 完成打印互补 macroelectronics 是困难的。在这研究，我们报导阀值电压 V < 潜水艇 class= “ a-plus-plus ” > 互补晶体管和 inverters 调节并且打印的 th 分别地作为 p 类型和 n 类型晶体管 CNT 和铟锌氧化物 IZO 的薄电影创作了。我们优化了 V <潜水艇class=“ a-plus-plus ”>由作为来源/排水管电极比较 Ti/Au 和 Ti/Pd 的p类型晶体管的 th ，并且观察到有 Ti/Au 电极的 CNT 晶体管展出了改进模式操作 V <潜水艇class=“ a-plus-plus ”> th 我<潜水艇class=“ a-plus-plus ”>在和改进模式操作 V 上<潜水艇class=“ a-plus-plus ”> th > 0 。例如，一在里面: 2:1 的 Zn 比率与 V 产出一只改进模式 n 类型晶体管 < 潜水艇 class= “ a-plus-plus ” > th 1 V 并且我 < 潜水艇 class= “ a-plus-plus ” > 在 5.2 A 的 上。而且，由打印，一部 CNT 薄电影和 IZO 变瘦一样的底层上的电影，我们与 99.6% 供应电压和 16.9 的电压获得的一个产量秋千制作了互补 inverter。这个工作为互补晶体管和电路显示出 p 类型 CNT 和 n 类型 IZO 的混合集成的诺言。

Preparation and characteristics of Nb-doped indium tin oxide thin films by RF magnetron sputtering

Niobium-doped indium tin oxide(ITO:Nb)thin films are fabricated on glass substrates by radio frequency(RF)magnetron sputtering at different temperatures.Structural,electrical and optical properties of the films are investigated using X-ray diffraction(XRD),atomic force microscopy(AFM),ultraviolet-visible(UV-VIS)spectroscopy and electrical measurements.XRD patterns show that the preferential orientation of polycrystalline structure changes from(400)to(222)crystal plane,and the crystallite size increases with the increase of substrate temperature.AFM analyses reveal that the film is very smooth at low temperature.The root mean square(RMS)roughness and the average roughness are 2.16 nm and 1.64 nm,respectively.The obtained lowest resistivity of the films is 1.2×10-4?.cm,and the resistivity decreases with the increase of substrate temperature.The highest Hall mobility and carrier concentration are 16.5 cm2/V.s and 1.88×1021 cm-3,respectively.Band gap energy of the films depends on substrate temperature,which is varied from 3.49 eV to 3.63 eV.

IGZO薄膜晶体管生物传感器无标记检测强直性脊柱炎

为了快速检测强直性脊柱炎血清学分子标志物人体白细胞抗原(HLA-B27),开发了一种基于人体白细胞抗原B27(HLA-B27)功能化的氧化铟镓锌(IGZO)薄膜晶体管生物传感器。利用射频磁控溅射技术和微纳加工工艺制备了IGZO薄膜晶体管(IGZO TFT),采用3-氨丙基三乙氧基硅烷(APTES)和抗体对IGZO TFT进行修饰,制备出针对HLA-B27检测的生物传感器。实验结果表明,功能化的IGZO TFT生物传感器具有稳定的电学特性和传感性能。传感器对HLA-B27的检测极限为1 pg/mL,在1 pg/mL至100 ng/mL的范围内均有良好的线性响应。这说明所设计的高性能生物传感器能够有效检测出强直性脊柱炎的标志物。此外,IGZO TFT可以扩展为传感器阵列平台,实现对某种疾病多种标志物的联合检测,在便携式床旁诊断设备的应用中具有巨大潜力。

射频磁控溅射工艺参数对掺钨氧化铟锡透明导电薄膜性能的影响

ITO薄膜是目前应用最为广泛的透明导电薄膜,通过在ITO中掺杂其他金属可以进一步改善ITO薄膜的光学和电学性能。本文采用射频(RF)磁控溅射法制备了掺钨氧化铟锡(ITO∶W)透明导电薄膜,研究了薄膜厚度、表面形貌、晶体结构以及光学和电学性能与各溅射参数之间的关系。当溅射功率大于40 W时,制备的ITO∶W薄膜为方铁锰矿结构的多晶薄膜,此时薄膜表面光滑平整而且具有良好的结晶性。在基板温度320℃、溅射功率80 W、溅射时间15 min、工作气压0.6 Pa条件下得到了光学和电学性能优良的ITO∶W薄膜,其方块电阻为10.5Ω/、电阻率为4.41×10^(-4)Ω·cm,对应的载流子浓度为2.23×10^(20)cm^(-3)、迁移率为27.3 cm^(2)·V^(-1)·s^(-1)、可见光(400~700 nm)范围内平均透射率为90.97%。此外,本研究还发现通过调节基板温度影响氧元素的状态可以改变ITO∶W薄膜的电学性能。

IAZO薄膜晶体管的制备与性能研究

为了探究退火温度对IAZO薄膜晶体管器件光电性能的影响,采用射频溅射单溅射法,并在(400~700)℃的范围内制备了一系列真空退火后的IAZO薄膜晶体管。分别对IAZO薄膜表面形貌、内部结构、元素组成和价态组成进行分析,采用半导体参数仪及搭配的探针台测试电学性能测试。采用紫外可见分光光度计测试薄膜透过率。结果表明,随着退火温度的升高,器件的电学性能先呈现上升趋势,达到峰值后开始下降。在500 ℃真空退火1 h后,IAZO TFT饱和迁移率为0.18 cm2/(V·s)、阈值电压为3.35 V、亚阈值摆幅为0.10 V/decade、开关比为1.13*108。IAZO薄膜透光率达到90 %以上、光学带隙达到4.1 eV,器件性能达到最佳。

低温快速制备基于溶液工艺的高性能氧化铟薄膜及晶体管

利用脉冲紫外线辅助热退火在200℃的低温条件下,5 min内制备了基于溶液工艺的氧化铟薄膜及薄膜晶体管.对比传统热退火,研究了脉冲紫外线辅助热退火对氧化铟薄膜的表面形态、化学结构和电学特性的影响.实验结果表明,脉冲紫外线辅助热退火方式能够在短时间内实现改善氧化铟薄膜的质量及薄膜晶体管的性能.原子力显微镜和场发射扫描电子显微镜结果显示该薄膜表面较传统热退火制备薄膜表面更为致密平坦.X射线光电能谱测试表明,脉冲紫外线辅助热退火处理后会产生氧空位,从而提高载流子浓度,改善了氧化铟薄膜的导电性.此外,对比研究了紫外线辅助热退火对氧化铟薄膜晶体管电气性能的影响.结果表明器件的电学特性得到了明显改善,亚阈值摆幅降低至0.12 mV/dec,阈值电压为7.4 V,电流开关比高达1.29×107,场效应迁移率提升至1.27 cm^(2)/(V·s).因此,脉冲紫外线辅助热退火是一种简单、快速的退火方式,即使在低温条件下也能快速提高氧化铟薄膜和薄膜晶体管的性能.