共查询到19条相似文献,搜索用时 151 毫秒
1.
采用化学镀金法在高阻p-CZT(CdZnTe)晶片表面制备Au电极,并用改进的圆环传输线模型(Ring-CTLM)测量了CZT电极的接触电阻,探讨了大气气氛下退火温度对CZT电极欧姆特性的影响.实验结果表明,200℃退火可以显著改善欧姆特性,使接触电阻率ρc显著减小,采用Ring-CTLM模型测得CZT与金电极接触电阻率为0.1524Ω·cm2.通过XPS分析了CZT与Au电极接触界面的成分,发现在Au/p-CdZnTe界面处形成了CdTeO3层,该界面层可起到载流子复合中心的作用,构建的新模型很好地解释了化学镀金法在p-CdZnTe晶片表面形成欧姆接触的机理. 相似文献
2.
3.
4.
Ti/Al/Ni/Au与n型GaN的欧姆接触研究 总被引:5,自引:0,他引:5
通过电流 电压 (I V)特性和传输线方法 (TLM )测量研究在n型GaN上淀积Ti/Al/Ni/Au电极形成欧姆接触的机制。Ni/Au作为Ti/Al的覆盖层起了阻止Ti ,Al,Au的互扩散及抗接触层氧化的作用。在 4 0 0℃到 90 0℃范围内 ,Ti/Al/Ni/Au与n型GaN的接触电阻随温度升高先略有上升 ,到 5 0 0℃以后单调下降。而表面形貌却在合金温度高于6 0 0℃以后随温度升高逐步变差。通过两步合金法得到了n GaN上Ti/Al/Ni/Au形成的接触电阻低达 9.6 5× 1 0 - 7Ωcm2 。最后还对两步合金法形成n GaN欧姆接触的机制进行了讨论。 相似文献
5.
6.
7.
在AlGaNpin型日盲紫外探测器结构中的p-AlGaN层上生长了Ni/Au和Pd/Au,并在600~850℃温度下进行快速热退火,测量其退火前后传输线模型中各金属接触间的电学性质。实验发现,Ni/Au与Pd/Au在p-AlGaN上表现出了不同的接触性能。为了更好的说明金属与p-AlGaN材料接触之间在退火后电流的变化,还测量了p-AlGaN材料裸片两点之间I-V曲线在退火前后的变化。实验表明,比起Ni/Au来,Pd/Au在p-AlGaN材料上制备欧姆接触具有一定的优势,并在文中进行了分析。 相似文献
8.
Zintl相Mg3(Sb,Bi)2基热电材料因在中低温区(27~500℃)表现出优异的热电性能而受到广泛关注。然而,由于Mg、Sb元素比较活泼,在长期高温服役下易与电极发生剧烈界面扩散反应,导致热电器件的性能和服役寿命衰减。因此,选择能有效阻挡元素剧烈互扩散并且具有低界面接触电阻率阻挡层材料至关重要。本研究首先利用热压工艺制备出300℃最高ZT~1.4的n型Mg3SbBi(Mg3.2SbBi0.996Se0.004)样品,然后采用Nb粉作为扩散阻挡层一步烧结制备Mg3SbBi/Nb/Mg3SbBi“三明治”结构样品,系统研究界面层的组成、微结构以及电阻随老化时间演变过程。加速老化实验(525℃/70 h; 525℃/170 h; 525℃/360 h)研究发现, Nb阻挡层中的Mg-Sb/Bi组分发生偏析,表面产生裂纹,抛光处理后界面连接完好,无裂纹和孔洞,界面扩散层厚度随老化时间延长缓慢增加至1.6μm。Nb/... 相似文献
9.
上海地铁接触网,多采双承双导柔性悬挂形式,直流1500V供电。随着使用年限的增加逐渐进人大修阶段。为进一步拓展上海城轨市场,本文结合我段在上海地铁一号线换线工程中的施工经验,以具体锚段为例,着重论述了上海地铁直流1500V接触网双接触线更换的施工工艺。 相似文献
10.
简单介绍了低温真空下固体界面间的接触热阻现象,搭建了一个能较精确测量圆柱型及薄片型材料间接触热阻的实验台。在真空环境下,测量了低温真空下Cu-Cu界面间的接触热阻。实验数据表明,接触热阻与压力、温度有关一定的依赖关系。最后,根据修正G-W模型,对实验结果进行了理论理论分析与比较,表明实验结果是正确的。 相似文献
11.
Kaifeng QinLinjun Wang Jiahua MinJijun Zhang Jian HuangXiaoyan Liang Ke TangYiben Xia 《Vacuum》2012,86(7):943-945
The characteristics of the Au contacts deposited by three different processes before and after accelerating aging tests have been investigated in this paper. The experimental results indicate that the aging tests can cause the degradation of the contact interfacial properties, such as continuities, adhesion strength and ohmic characteristics, especially for the contact electrode deposited by the thermal vacuum evaporation, which would influence the performance of CdZnTe detectors. 相似文献
12.
13.
对于拉杆柔性组合转子轴承系统,其接触界面类型复杂、数量众多,是影响其动力特性的众多因素之一。以拉杆柔性组合转子轴承系统各轮盘间的接触界面为考察对象,根据接触界面压力结合微观模型有限元分析,得到其宏观尺寸下的界面接触刚度。采用无质量无长度的均质面弹簧对接触界面进行等效,推导了接触界面作为附加弹簧单元对系统产生附加刚度矩阵的一般形式,并完成了计及接触界面效应的系统动力学建模。结合应用计及轴向力的铁木辛格梁轴单元的整体转轴建立的有限元模型,得到系统的动力学方程。而后采用打靶法和Floquet稳定性判别理论对系统进行分析求解,得到了计入接触界面影响后系统的稳定性边界和分叉形式,数值结果表明接触界面对不平衡组合转子的动力特性影响不可忽略。 相似文献
14.
15.
以甲基丙烯酸羟乙酯(HEMA)、N乙烯吡咯烷酮(NVP)、丙烯酰胺(AM)、甲基丙烯酸甲酯(MMA)、甲基丙烯酸乙酯(EMA)或者甲基丙烯酸丁酯(BMA)为原料,采用本体共聚法制备水凝胶角膜接触镜材料。采用环境扫描电子显微镜(ESEM)研究各单体对水凝胶结构的影响,结果表明,在溶胀状态下,HEMA的均聚物水凝胶结构均匀,而HEMA与NVP共聚物水凝胶在微米层次上出现含水量不均;在脱水状态下,HEMA的均聚物以及HEMA与NVP共聚物表现出均匀的结构,HEMA与AM共聚物呈纤维状,而HEMA、NVP与MMA、EMA或者BMA共聚物均出现微米级塌缩。 相似文献
16.
A.P.S. Selvadurai 《International Journal of Engineering Science》2003,41(7):721-739
This paper examines the axisymmetric elastostatic problem related to the unilateral receding contact at a pre-compressed smooth bimaterial elastic interface. The separation at the interface is caused by the action of axisymmetric stress fields of unequal magnitude, which are applied at any location of the separate halfspace regions. The analysis of the problem focuses on the determination of the zone of separation as a function of the pre-compression, the magnitudes and locations of the axisymmetric stress fields inducing the separation, and the elasticity characteristics of the halfspace regions. It is found that the radius of the separation zone can be evaluated in explicit form. In the particular instance when the loadings applied at the surface of the halfspace regions are equal in magnitude and distribution, the analysis reveals that the radius of the separation zone is independent of the elasticity properties of the halfspace regions and can be evaluated in exact closed form. 相似文献
17.
Giant Polarization Sustainability in Ultrathin Ferroelectric Films Stabilized by Charge Transfer 下载免费PDF全文
Sirui Zhang Yinlian Zhu Yunlong Tang Ying Liu Shuang Li Mengjiao Han Jinyuan Ma Bo Wu Zuhuang Chen Sahar Saremi Xiuliang Ma 《Advanced materials (Deerfield Beach, Fla.)》2017,29(46)
Ferroelectricity is generally deteriorated or even vanishes when the ferroelectric films are downsized to unit cell scale. To maintain and enhance the polarization in nanoscale ferroelectrics are of scientific and technological importance. Here, giant polarization sustainability is reported in a series of ultrathin PbTiO3 films scaled down to three unit cells grown on NdGaO3(110) substrates with La0.7Sr0.3MnO3 as bottom electrodes. Atomic mappings via aberration‐corrected scanning transmission electron microscopy demonstrate the robust ferroelectricity for the sub‐10 nm thick film. For the 1.2 nm thick film, the polarization reaches ≈50 µC cm?2. The 2 nm thick film possesses a polarization as high as the bulk value. The films ranging from 10 to 35 nm display a giant elongation of out‐of‐plane lattice parameter, which corresponds to a polarization of 100 µC cm?2, 20% larger than that of the bulk PbTiO3. The giant enhancement of polarization in the present films is proposed to result from the charge transfer at the La0.7Sr0.3MnO3/PbTiO3 interface, as supported by the anomalous decrease of Mn valence measured from X‐ray photoelectron spectroscopy. These results reveal the significant role of charge transfer at interfaces in improving large polarizations in ultrathin ferroelectrics and are meaningful for the development of future electronic devices. 相似文献
18.
Srikanth Hariharan P K Mukhopadhyay A K Raychaudhuri 《Bulletin of Materials Science》1991,14(3):759-761
The nonlinear current voltage characteristics of a point contact convey information about various excitations in the metal.
We have made a point contact study on a superconductor to see the band gap and on a normal metal to see the transport characteristics. 相似文献