基底温度对直流磁控溅射ITO透明导电薄膜性能的影响

用直流磁控溅射法制备透明导电锡掺杂氧化铟(ITO)薄膜,靶材为ITO陶瓷靶,组分为m(In2O3):m(SnO2)=9:1.运用分光光度计,四探针测试仪研究了基底温度对薄膜透过率、电阻率的影响,并用X射线衍射(XRD)仪对薄膜进行结构分析.计算了晶面间距和晶粒尺寸,分析了薄膜的力学性质.实验结果表明,在实验设备条件下,直流磁控溅射ITO陶瓷靶制备ITO薄膜时,适当的基底温度(200℃)能在保证薄膜85%以上高可见光透过率下,获得最低的电阻率,即基底温度有个最佳值.薄膜的结晶度随着基底温度的提高而提高.     

探析PI薄膜的性能及生产应用

首先对PI薄膜进行性能分析,然后就其应用和同类薄膜产品进行比较,最后对其广泛应用进行归纳总结,并对未来电子级PI薄膜技术展望。     

喷墨印刷沉积的PEDOT/PSS薄膜导电性能

利用压电喷墨印刷技术沉积了PEDOT/PSS有机导电薄膜,研究了退火温度和乙二醇掺杂对薄膜导电性能的影响。实验结果表明:未退火和退火温度为120,140,160℃时,薄膜表面平均粗糙度分别为8.15,4.10,3.36,2.66nm;乙二醇掺杂使导电激活能由未掺杂时的0.096eV减小为0.046eV;电导激活能减小表明PEDOT分子链从低电导率的卷曲构象向高电导率的伸展构象转变;此外,乙二醇掺杂促使PSS与PE-DOT/PSS分离,使团聚的PEDOT/PSS颗粒变小从而分散更均匀,降低了表面粗糙度。     

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。     

薄膜厚度对ZnO：Zr透明导电薄膜光电性能的影响

利用射频磁控溅射法在室温水冷玻璃衬底上制备出了可见光透过率高、电阻率低的ZnO:Zr透明导电薄膜.讨论了厚度对ZnO:Zr透明导电薄膜光学、电学性能的影响.当薄膜厚度为213 nm时,薄膜电阻率达到最小值1.81×10-3 Ω·cm.所制备的薄膜样品都具有高透光率,其可见光区平均透过率超过了93.0%.当薄膜厚度从125 nm增加到350 nm时,薄膜的光学带隙从3.58 eV减小到3.50 eV.     

铝钛共掺杂氧化锌透明导电薄膜的制备与性能研究

用直流磁控溅射法在玻璃衬底上成功制备出了铝钛共掺杂氧化锌(TAZO)透明导电薄膜,研究了溅射压强对TAZO薄膜的微观结构和光电特性的影响。研究结果表明,所制备的TAZO薄膜为六角纤锌矿结构的多晶薄膜,且具有c轴择优取向。当溅射压强为7.5Pa时,薄膜的最小电阻率为3.34×10-4Ω.cm。薄膜的可见光区平均透过率大于89%。溅射压强对薄膜的电阻率和微观结构有显著影响。     

透明导电氧化物薄膜研究的新进展

透明导电氧化物(TCO)薄膜因其良好的光电性能,在光电器件上应用广泛,且已成为研究热点.p型TCO薄膜的出现开辟了透明导电氧化物研究的新领域,红外透明导电氧化物薄膜拓展了TCO薄膜的应用范围.该文综述了近几年p型TCO薄膜的研究进展,并简单介绍了新兴的红外透明导电氧化物薄膜的研究进展.     

薄膜太阳电池用改进型绒面结构MOCVD-ZnO:B透明导电薄膜研究

利用低压MOCVD技术在玻璃衬底上生长了改进型绒面结构ZnO:B薄膜。改进型ZnO:B薄膜包含两层薄膜,第一层采用传统工艺技术生长了类金字塔状晶粒,第二层借助相对低温生长技术获得了类球状晶粒。典型的双层生长技术获得的MOCVD-ZnO:B薄膜具有相对高的电子迁移率~27.6 cm2/Vs,主要归因于提高了晶界质量,减少了缺陷态。随着第二层修饰层厚度的增加,MOCVD-ZnO:B薄膜的绒度提高,而光学透过率有所下降。相比于传统工艺生长的ZnO薄膜,双层结构的MOCVD-ZnO:B薄膜应用于硅基薄膜太阳电池展现了较高的太阳电池转化效率。     

SnO2-x透明导电薄膜的制备及其导电性能研究

以金属有机化合物(MO)四甲基锡[Sn(CH3)4]为源物质,采用等离子体增强化学气相沉积技术(PECVD),在玻璃片上制备了SnO2–x薄膜。并用XRD、AFM等对样品进行分析。结果表明,氧气与四甲基锡(氮气携带)流量比为10:6,衬底温度为150℃,淀积时间为2h制备的薄膜表面平整,方块电阻大约为36.5?/□,紫外–可见光透射率在90%以上。     

铜纳米线柔性透明导电薄膜的制备和性能研究

为寻找替代硬质氧化铟锡的新型柔性透明导电薄膜,采用液相还原法制备了大长径比的铜纳米线,并利用喷涂法实现铜纳米线柔性透明导电薄膜的制备。采用透射电子显微镜、扫描电子显微镜、X射线衍射仪对形貌和相结构进行了分析,并用紫外可见分光光度计和四探针测试仪分别对铜纳米线柔性透明导电薄膜的电学性能和光学性能进行了表征测试。结果表明,铜纳米线直径约为40 nm,长度为10～20μm,具有高长径比、分散性好、形貌规整的特点。同时,铜纳米线薄膜的电学和光学性能优异,方阻约为100Ω/,在550 nm处的光透射率为82%左右。该薄膜还具有较好的温度稳定性,耐温可达110℃,且其方阻在不同弯折程度下变化不大,具有良好的抗弯折性,可用于柔性可穿戴电子产品。     

Thermopower,d.c. electrical conductivity and thermal resistivity of SiOx thin films

SiO_x thin films, with planar geometry, were deposited to a thickness of 130 nm at a rate of 0·4 nms^?1 on Corning 7059 glass substrates held at 20°C by thermal evaporation in vacuo?1 mPa. Thermopower and d.c. electrical conductivity measurements indicate that non-polaronic holes are the probable current carriers below 430 K whilst small polarons dominate above 430 K. The hopping energy for polaronic conduction varied from ～0meV at 430K to 50meV at 510K. The Debye temperature was estimated from thermal resistivity measurements to increase from 800 K to 1030K as the substrate temperature increased from 100 K to 510 K. Acoustical phonons are probably responsible for the heat transfer process.     

Dislocation electrical conductivity of synthetic diamond films

A relationship between the electric resistance of single-crystal homoepitaxial and polycrystalline diamond films and their internal structure has been investigated. It is established that the electrical conductivity of undoped homoepitaxial and polycrystalline diamond films is directly related to the dislocation density in them. A relation linking the resistivity ρ (～10¹³–10¹⁵ Ω cm) with the dislocation density Γ (～10¹⁴?4 × 10¹⁶ m^?2) is obtained. The character of this correlation is similar for both groups of homoepitaxial and polycrystalline diamond films. Thin (～1–8 μm) homoepitaxial and polycrystalline diamond films with small-angle dislocation boundaries between mosaic blocks exhibit dislocation conductivity. The activation energy of dislocation acceptor centers was calculated from the temperature dependence of the conductivity and was found to be ～0.3 eV. The conduction of thick diamond films (h > 10 μm) with the resistivity ρ ≈ 10⁸ Ω cm is determined by the conduction of intercrystallite boundaries, which have a nondiamond hydrogenated structure. The electronic properties of the diamond films are compared with those of natural semiconductor diamonds of types IIb and Ic, in which dislocation acceptor centers have activation energies in the range 0.2–0.35 eV and are responsible for hole conduction.     

Modelling and IR measurement of the electronic substrate thermal conductivity

The temperature distribution on a ceramic substrate with a small heating element in the middle has been measured by infrared thermography. By comparing the experimental data with a theoretical analysis, the thermal conductivity could be easily obtained.     

Influence of the law of electrical conductivity on thermal switching and breakdown

Influences of the law of electrical conductivity σ on thermal switching and breakdown events were investigated. The conductivities selected weresigma_{1}propto exp(aT), orsigma_{1}propto exp(-B/T), and also voltageVdependentpropto exp (bV), whenTis temperature and a, B, and b are constants. Simple models, thin film, and cylindrical specimens were considered. The influence of σ was examined by comparing steady-state V-I characteristics, the values of maximum voltages Vm, times for temperature runaway when voltages larger than Vmwere applied, and instabilities in the negative differential resistance ranges. Some significant differences were found as σ1rises much faster with temperature than σ2. Thus current filaments were very narrow whensigma_{1}propto exp(aT), but orders of magnitude wider whensigma_{1}propto exp(-B/T). For a given current, much larger temperature rises occur in the σ2than in the σ1case of conductivity. Transition to a branch line V-I characteristic and filament formation can occur in the σ2case at considerably higher temperatures than in the σ1case.     

Amorphous boron films with enhanced electrical conductivity

The results of studying the electrical properties of nanostructured films of amorphous boron a-B are compared with the results obtained for bulk samples of the same material and also for the crystals of certain quasi-amorphous borides with complex icosahedral structure. Models accounting for the enhanced electrical conductivity of amorphous boron films are suggested.     

基于高亮度LED散热基板导热系数的检测方法

导热系数在化工、建筑、科研生产中有着广泛的应用。目前国内外关于导热系数的检测方法很多,相关的标准也不少。检测样本不同,对检测方法的适用领域、测量范围和精度的要求也不同。在检测时,选择合适的检测方法至关重要。通过对比分析国内外各种导热系数的检测方法,引入一种适合印制电路板行业高亮度LED散热基板导热系数的新检测方法。通过试验验证,确定其在高亮度LED散热基板的导热系数检测方面的适用性。     

Influence of charge effects on the electrical conductivity of thin metal films

The letter describes investigations made into the electrical resistance of evaporated films of lead, tin, indium and gold, less than 600 m? thick. It was found that lower-resistance films could be obtained if arrangements were made to reduce the accumulated charge appearing on the substrate.     

Properties of discontinuous gold thin films deposited on a silicon substrate

Experimental results on the dependence on deposition conditions of the electrical resistance and gauge factor of discontinuous gold films in the vicinity of the percolation threshold are reported. The three-dimensional nature of the films is emphasized. The gauge factor reveals anomalous behaviour.     

Characterization of the thermal conductivity of insulating thin films by scanning thermal microscopy

This paper reports on the abilities of a Scanning Thermal Microscopy (SThM) method to characterize the thermal conductivity of insulating materials and thin films used in microelectronics and microsystems. It gives a review of the previous works on the subject and gives new results allowing showing the performance of a new method proposed for reducing the thermal conductivity of meso-porous silicon by swift heavy ion irradiation. Meso-porous silicon samples were prepared by anodisation of silicon wafers and underwent irradiation by 845 MeV ²⁰⁸Pb ions, with fluences of 4×10¹¹ and 7×10¹¹ cm⁻². Thermal measurements show that irradiation reduced thermal conductivity by a factor of up to 2.     

Dependence of electrical and optical properties of ZnO films on substrate temperature

ZnO films were prepared by filtered cathodic vacuum arc technique with Zn target at different substrate temperatures. The crystallinity is enhanced with increasing substrate temperature and preferably oriented at (1 0 3) direction when the substrate temperature is higher than 230°C. The PL emission corresponding to the exciton transition at 3.37 eV can be observed at room temperature, which indicates that high-quality films have been obtained by this technique. The Hall mobility, which increases with substrate temperature, is dominated by grain boundary scattering.