碳化硅薄膜制备及其场发射特性

采用热丝化学气相沉积法在Si（111）、Ti（101）衬底上制备了SiC薄膜,并利用X射线衍射和傅里叶变换红外吸收光谱（FTIR）对薄膜的结构、成分及化学键合状态进行了分析．XRD结果表明,制备的SiC薄膜呈现3C-SiC结晶相,有很好的择优取向性．HIR谱显示,薄膜的吸收特性主要为Si-C键的吸收,其吸收峰为804．95cm^-1．从原子力显微镜对SiC薄膜表面形貌的测试分析可以看出,样品表面呈规则精细颗粒状结构且薄膜结构致密．此外,在高真空系统中（6．0×10^-4Pa）对生长的SiC薄膜进行场敛发射特性测试,结果表明生长的SiC薄膜具有场致发射特性：样品的开启电压为82．1V／μm,最大电流密度为631．5μA／cm^2．     

金刚石薄膜场致发射材料的特性与应用

主要论述金刚石薄膜场致发射材料的性能，包括了多晶金刚石薄膜、类金刚石薄膜（DLC）、纳米结构金刚石薄膜、用酸处理后的金刚石薄膜等的性能，给出了几种典型的金刚石薄膜场致发射阴极结构。     

等离子体表面氮掺杂对非晶碳膜场发射特性的影响

氢化非晶碳膜作为一种场致阴极电子发射材料已被广泛研究,通过对薄膜进行掺杂以提高其场发射特性已被证明是行之有效的方法之一.利用常规等离子体化学气相淀积技术制备了氢化非晶碳薄膜材料,在原位利用氮等离子体对碳膜表面进行N型掺杂.通过不同手段研究了氮表面掺杂前后非晶碳膜的微结构和化学键的变化,对表面掺杂前后的薄膜的场电子特性的测量表明,在氮表面掺杂后其场电子发射特性有了明显改善,特别是场发射的阈值电场从掺杂前的3.2 V/μm下降到掺杂后的1.0 V/μm.初步实验分析表明:由于氮表面掺杂后,在碳膜表面形成N-H键,从而导致碳膜表面的有效功函数降低使场电子发射特性得以提高.     

场致发射显示屏技术的研究

介绍了场致发射显示技术的工作原理及特点，分析了微尖型场致发射阴极、膜状型场致发射阴极的场致电子发射特性，对场致发射显示屏（FELLS）的结构做了研究，并讨论了影响场致发射显示屏性能的主要因素及改进的措施．     

硅烷自组装膜对PPy固体铝电解电容器的影响

通过对比在固体铝电解电容器多孔性绝缘Al2O3膜表面是否进行硅烷偶联剂预处理后化学聚合得到的导电聚吡咯（PPy）薄膜的连续性、附着性与电导率以及所得PPy固体铝电解电容器的性能指标,探讨了硅烷自组装膜对PPy薄膜与PPy固体铝电解电容器性能的影响及硅烷自组装膜在多孔性Al2O3膜表面的形成机理与PPy薄膜在硅烷自组装膜上的成膜机理．PPy薄膜的电导率从5．4s·cm-1提高到了16．6S·cm-1,PPy固体铝电解电容器的损耗角正切tgδ≤0．06（120Hz,20℃）,漏电流IL≤〈0．04CV（或3μA）．     

LiClO4有机高分子电解质的电致变色效应

研究了聚甲基丙烯酸甲酯为基的PC LiClO4有机高分子电解质薄膜的制备、特性及其在电致变色器件中的应用.采用溶胶-凝胶法制备有机高分子电解质,当LiClO4的浓度为1.5 mol/L时,电解质的电导率达到最大值2.0 mS/cm.将此样品作为离子传输层与NiOχ电致变色薄膜构成全固态电致变色器件,在紫外光辐照区域,光密度差大于1.66,在350～850 nm光区范围内,光密度差为0.83～1.66,在可见光区和近红外区都具有优良的变色性能.     

一种基于纳米碳管的常开型后栅极场致发射显示板

提出了一种常开型后栅极场致发射显示板及其工作原理．该显示板直接利用阳极使阴极产生场致电子发射,而通过埋在阴极之下的栅极上施加低于阴极电压的电压来阻止阴极产生场致电子发射,从而来调制显示所需图像．文中采用有限元法对该场致发射器件的电场强度分布进行了模拟计算,并研究了该器件中阴极的发射特性．计算结果表明在该场致发射显示板中,阴极发射均匀性好,发射面积大,从理论上证明了该常开型后栅极场致发射显示板工作原理的可行性．     

金属／聚酰亚胺LB薄膜界面特性研究

为提高有机电子器件的性能,制备了不同的厚度的聚酰亚胺（PI）LB薄膜,测量了不同厚度的聚酰亚胺LB薄膜与金电极接触时的表面电压,分析了金属／PILB薄界面的电荷分布情况,发现电荷主要集中在界面附近,测定了金属／PILB／金属结构的电流－电压关系,用金属热电子发射和场致发射的模型对其进行了分析,结果表明电子发射机理受温度和电场强度的控制,实验结果与模型符合得较好。     

内场助结构Ag-O-Cs光电发射薄膜真空制备研究

通过掩膜预处理和挡板转移技术的配合,利用真空沉积方法首次制备了内场助结构Ag-O-Cs 光电发射薄膜。Ag-O-Cs薄膜内场助光电发射特性测试结果表明,该方法能够有效地实现Ag-O-Cs 薄膜体内电场的加载与表面电极的引出,薄膜光电灵敏度随内场偏压的增大而上升。Ag-O-Cs 薄膜在内场作用下的光电发射增强现象与薄膜体内能带结构变化、低能电子参与光电发射等物理机制有关。     

化学聚合制备的透明导电性聚苯胺／聚对苯二甲酸乙二酯复合薄膜

通过将经预处理的聚对苯二甲酸乙二酯（ＰＥＴ）薄膜浸入ＨＣｌ、氧化剂和苯胺的水溶液进行化学聚合制得了高度透明和导电的ＰＡｎ（聚苯胺）／ＰＥＴ复合薄膜．这种技术是获得透明导电高分子薄膜的一种优良工具．本文提供的数据可能会促进ＰＡｎ／ＰＥＴ复合薄膜作为一种新的功能材料的实际应用。     

Fabrication of multilayer films from regenerated cellulose and graphene oxide through layer-by-layer assembly

A key challenge in the preparation of nanoplatelet-filled polymer composites is the ability to realize the nanometer-level dispersion and the planar orientation of nanosheets in polymer matrices. In this report, multilayer films were successfully fabricated by layer-by-layer assembly of regenerated cellulose and graphene oxide, in which graphene oxide nanosheets were used as the building blocks. The thickness of 50 layer film is about 20 mm and it exhibits a high degree of smoothness. This may be attributed to the well-defined layered structure with high degree of planar orientation and nanolevel assemblies of graphene oxide nanosheets in the polymer matrices. Typical field emission scanning electron microscope images demonstrate an ordered arrangement of layers. The electrical conductivity of the multilayer films shows a remarkable increase with increasing layer of the films. A significant enhancement of mechanical properties has been achieved, that is, a 110.8% improvement of elastic modulus and a 262.5% increase of hardness respectively.     

氮化硼薄膜的厚度对场发射特性的影响

利用射频磁控溅射方法, 在n型（100）Si基底上沉积了不同厚度（54~124 nm）的纳米氮化硼（BN）薄膜. 红外光谱分析表明, BN薄膜结构为六角BN（h-BN）相(1 380 cm^-1和780 cm^-1)结构. 在超高真空系统中测量了不 同膜厚的场发射特性, 发现阈值电压随着厚度的增加而增大. 厚度为54 nm的BN薄膜样品阈 值电场为10 V/μm, 当外加电场为23 V/μm时, 最高发射电流为240 μA/cm². BN薄膜场发射F-N曲线表明, 在外加电场作用下, 电子隧穿了BN薄膜表面势垒发射到真空.     

基底偏压对氮化硼薄膜场发射特性的影响

利用射频磁控溅射方法, 在n型（100）Si（0.008～0.02 Ω·m）基底上沉积了氮化 硼（BN）薄膜. 红外光谱分析表明, BN薄膜结构均为六角BN（h-BN）相. 在超高真空系统中 测量了BN薄膜的场发射特性, 发现BN薄膜的场发射特性与基底偏压关系很大, 阈值电场随基 底偏压的增加先增加后减小. 基底偏压为-140 V时BN薄膜样品场发射特性要好于其他样品, 阈值电场低于8 V/μm. F~N曲线表明, 在外加电场的作用下, 电子隧穿BN薄膜表面势垒发射 到真空.     

基底温度对氮化硼薄膜场发射特性的影响

利用射频磁控溅射方法， 真空室中充入高纯N_{2(99.99%)和高纯Ar（99.99%）的混合气体， 在n型（100）Si基底上沉积了六角氮化硼（h-BN）薄膜. 在超高真空（<10^-7 Pa）系统中测量了BN薄膜的场发射特性， 发现 沉积时基底温度对BN薄膜的场发射特性有很大影响. 基底温度为500 ℃时沉积的BN薄膜样品场发射特性要好于其他薄膜， 阈值电场为12 V/μm， 电场升到34 V/μm， 场发射电流为280 μA/cm². 所有样品的Fowler-Nordheim(F-N)曲线均近似为直线， 表明电子是通过 隧道效应穿透BN薄膜发射到真空的.}     

Field emission of SiCN thin films bombarded by Ar<Superscript>+</Superscript> ions

SiCN thin films were synthesized by a radio frequency chemical vapor deposition (RFCVD) system on P-type Si (1 0 0) wafers using C₂H₄, SiH₄ and N₂ as raw materials, In order to get rid of the oxygen absorbed on the surface and improve the characteristics of electron field emission, Ar⁺ ions of low energy were used to bombard the samples. The field emission characteristics of SiCN thin films before and after Ar⁺ bombardment were studied in the super vacuum environment of 10⁻⁶ Pa. It was showed that the turn-on field (defined as the point where the current-voltage curve shows a sharp increase in the current density) decreased from 38 V/μm before bombardment to 25 V/μm after bombardment. And the maximum emission current density increased from 159.2 to 267.4 μA/cm². The composition before and after Ar⁺ bombardment was compared using X-ray photoelectron spectroscopy (XPS). Our results illustrated that the field emission characteristics were improved after the bombardment of Ar⁺. Foundation item: Supported by the National Natural Science Foundation of China (19975035) Biography: Ma You-peng (1978), male, Master candidate, research direction: novel functional materials film and ion beam modification of materials.     

Simple method to rapidly fabricate chain-like carbon nanotube films and its field emission properties

A simple process to fabricate chain-like carbon nanotube (CNT) films by microwave plasma-enhanced chemical vapor deposition (MPCVD) was developed successfully. Prior to deposition, the Ti/Al₂O₃ substrates were ground with Fe-doped SiO₂ powder. The nano-structure of the deposited films was analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The field electron emission characteristics of the chain-like carbon nanotube films were measured under the vacuum of 10-5 Pa. The low turn-on field of 0.80 V/μm and the emission current density of 8.5 mA/cm2 at the electric field of 3.0 V/μm are obtained. Based on the above results, chain-like carbon nanotube films probably have important applications in cold cathode materials and electrode materials.     

Development of Numerical Model for Radio Frequency Atmospheric Pressure Glow Discharges in Argon

A one-dimensional,self-consistent fluid model is developed for a computational investigation on discharge characteristics and dynamics of radio frequency (RF) glow discharges in atmospheric argon,which are demonstrated through the spatial and temporal profiles of plasma species,electric field,and mean electron energy.Furthermore,in the discharge current density range from 7.1 mA/ cm2 to 119.5 mA/cm2,different discharge operation modes of α and γ are indicated by changing differential conductivity of voltagecurrent characteristics and sheath dynamics in terms of sheath voltage and sheath thickness.     

Improvement in the intense pulsed emission stability of grown CNT films via an electroless plated Ni layer

Carbon nanotube(CNT)films were grown on silicon wafers with and without a nickel layer(Si-CNT and Ni-CNT)via the pyrolysis of iron phthalocyanine.The nickel layer was prepared using the electroless plating method.To study the emission stability of Si-CNT and Ni-CNT cathodes during intense pulsed emission,emission characteristics were measured repeatedly with a diode structure using a Marx generator as a voltage source.For the peak values of the pulsed voltage,which were in the range between 1.62-1.66 MV(corresponding to electric field intensities between 11.57-11.85 V/μm),the first cycle emission current was 109.4 A for Si-CNT and 180.5 A for Ni-CNT.By comparing the normalized emission currents of the Si-CNT and Ni-CNT cathodes,the improvement in the emission stability can be easily quantified.The number of emission cycles necessary for the peak current to decay from 100%to 50%increased from~3 for Si-CNT to~11 for a Ni-CNT film.     

湿式电迁移烟气脱硫技术研究

介绍了湿式电迁移烟气脱硫试验,利用SO2在放电条件下能俘获电子形成负离子,并在电场作用下发生迁移的特性,将电晕放电和湿式水膜结合起来进行烟气脱硫．通过模拟试验,研究了模拟烟气参数、反应器结构及放电特性等因素对SO2电迁移和脱硫效率的影响．试验结果表明：SO2在放电电场中具有电迁移的能力,系统脱硫效率随电压升高、放电区长度和输入功率增加而增加,脱硫效率可以达到90％以上．     

红光染料掺杂聚合物薄膜的放大自发发射特性

利用355 nm 三倍频Nd ∶ YAG激光器为泵浦源, 研究红光染料(DCJTB)在聚苯乙烯、 聚甲基丙烯酸甲酯和聚N-乙烯基咔唑三种聚合物基体薄膜中放大的自发发射(ASE)特性. 结果表明, DCJTB/聚N-乙烯基咔唑薄膜表现出很强的ASE, 具有高增益和低阈值的特性, 是一种比较优良的有机聚合物薄膜激光材料体系.