生长ZnO薄膜的氧分压对ZnO/PS体系光学性能的影响

采用电化学阳极氧化法,在p型（100）晶向的单晶Si片上制备多孔Si（PS）样品;以PS为衬底,采用射频反应磁控溅射技术在不同O2分压下沉积ZnO薄膜。X射线衍射（XRD）结果显示,所有ZnO/PS复合体系在衍射角为34.24°附近均出现较强的衍射峰,对应于ZnO的（002）晶面,说明样品具有良好的c轴择优取向;但由于...     

纳米硅颗粒在多孔氧化铝中的光致荧光特性

采用阳极氧化方法制备了多孔硅（Ps），经过超声波充分粉碎PS层得到分散的si纳米颗粒（n-Si），利用高速离心旋转方法将n-si镶嵌到多孔氧化铝（Al2O3）模板中，得到nSi／Al2O3。复合体系。研究了PS、分散的n-Si和n-Si／Al2O3。的荧光（PL）光谱性质，观察到n-Si极强的蓝紫光发射。结果表明，在Al2O3模板中的n-Si，比起PS和丙酮中的发光峰值波长向短波方向“蓝移”，而且半峰全宽（FWHM）也相对变窄。实验现象表明，量子限制效应（QCE）对样品的PL性质有苇要作用，并用QCE对样品的发光“蓝移”现象进行了解释。     

室温Si-玻璃直接键合技术研究

将表面亲水性处理过的玻璃和Si片在室温、大气的环境下干燥,进行温度为150C以下、时间为20～200h的预键合。预键合后,Si和玻璃基片表面能有显著的提高,水分子和Si表面Si-OH原子团中的O原子连在一起,OH团数量增加了许多,形成较多的H键。预键合的Si-玻璃基片在200C下退火．消除由Si、玻璃热膨胀系数和热传导系数差异引起的诱导应力。2基片的Si-OH间发生聚合反应．产生水及si-O键,使得基片键合的表面能得到了更好的提高、测量了室温键合时间对Si玻璃表面能力的影响以及退火时间对键合强度的影响。实验结果证明．这项技术对Si-玻璃器件的键合十分有效。     

多孔硅/聚合物复合膜等效折射率的研究

用多孔Si（PS）圆柱空腔二维结构模型,理论研究了TE模式情况下PS／聚合物复合膜的等效折射率,给出了PS等效折射率与孔隙率和嵌入率的关系。实验采用波导耦合m线法分别研究了TE模和TM模入射情况下（633nm波长处）,孔隙率为73%的PS膜嵌入聚合物聚合基丙烯酸甲酯（PMMA）材料后的等效折射率与聚合物嵌入率的关系。理论分析与实验结果基本符合。     

基于电感耦合氧等离子体金刚石膜表面修饰的功率优化

采用电感耦合等离子体（ICP）氧等离子体刻蚀金刚石膜,探寻金刚石膜表面处理的方法。通过分析不同ICP射频源功率和不同偏压源功率下的刻蚀速率,研究了金刚石膜刻蚀的机理作用;通过拉曼光谱进行表征,分析刻蚀前后sp2与sp3的含量。结果表明,在ICP氧等离子体刻蚀的过程中,sp3键部分转化为sp2键;刻蚀后表面粗糙度降低;当...     

H2-O2混合气氛刻蚀制备金刚石纳米晶薄膜

提供了在镜面抛光Si衬底上沉积平滑的纳米金刚石（NCD）薄膜的方法。采用微波等离子体化学气相沉积（CVD）系统，利用H2、CH4和O2为前驱气体，在镜面抛光的Si基片上制备了直径为5cm的NCD薄膜，用扫描电镜（SME）和共焦显微拉曼光谱分析其表面形貌和结构特点。分析表明，利用这种方法可以制备出高sp^3含量的NCD薄膜。通过与沉积时间加长而沉积条件相同情况下合成的金刚石微晶薄膜形貌相对比，分析了H2-O2混合气氛刻蚀制备NCD薄膜的机理。分析表明，基底的平滑度对O2的刻蚀作用起到重要的影响；在平滑的基底上，含量较少的O2的刻蚀作用也很明显；随着基底的平滑度下降，混合气氛中O2的刻蚀作用逐渐减弱。     

用STM研究HF,O_2和H_2O混合气体对Si(100)表面的作用

用STM观测了Si（100）表面被氧气流携带的HF和H2O处理后的表面原子结构．实验在大气环境和室温条件下进行，所得STM拓扑图具有清晰的原子级的分辨率．结果表明处理后的表面结构随时间发生变化．刚处理后的表面不显示有序的结构特征，但在大气中存放15分钟后，硅片表面开始逐渐呈现出清晰的Si（100）2×1结构，随后再逐渐转变为1×1结构．这可能是混合气体与Si表面作用，能更有效地清除表面残余的沾污物和氧化层，暴露清洁的硅2×1再构表面，进一步由于吸附H，使表面悬挂键被氢原子占据，转变为1×1结构．有序结构可维持3小时，因此用所述混合气体处理硅     

离子束增强沉积氮化硅膜的分析

在电子束蒸发沉积硅的同时用25KeV氮离子进行轰击，在GH37合金表面合成Si3N4膜，用IR、XRS、XRD、TEM和AES-PRO对膜的组分和结构进行综合分析，表明离子束增强沉积（IBED）积成的薄膜之化学式为Si3N4，膜的主要结构是无定形态，局部区域存在少量Si3N4、Si2N4O、SiO2晶体和多晶Si。膜和基体之间存在一个大约50nm的界面混合区。     

氧等离子体对GaNHEMT器件的影响

研究了不同条件下氧等离子体对GaN器件表面的影响。在合适的条件下,氧等离子体可以使AlGaN表面发生氧化,形成Al2O3薄氧化膜,提高肖特基势垒,从而降低GaN器件的阈值电压,提高器件导通电流。该结果可望用于更高性能AlGaN/GaN HEMT器件制备的应用中。     

制备及钝化条件对多孔硅发光性能的影响

研究了氧化电流密度对多孔硅（PS）PL谱的影响。结果表明，随着氧化电流密度增大，PS的微晶Si平均尺寸减小，且尺寸的微晶Si数量也减少，说明制备条件对钝化PS的发光有影响；PS经适当的高温氧化处理后，其PL谱会发生明显变化；选用含有胺基的正丁胺，采用射频辉光放电法对PS进行钝化处理，在一定程度上提高了PS的发射强度伴随发光峰值的较大蓝移；其钝化PS的荧光谱随钝化温度和钝化时间变化，说明钝化条件对钝化PS的发光有直接影响。由此，可以通过调节制备和钝化条件来获得最大的发光效率和所需要的发光颜色。     

Progress of power field effect transistor based on ultra-wide bandgap Ga2O3 semiconductor material

As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(～ 4.8 eV) and large Baliga's figure of merit(BFOM) of Ga_2O_3 make it a potential candidate material for next generation high-power electronics, including diode and field effect transistor(FET). In this paper, we introduce the basic physical properties of Ga_2O_3 single crystal, and review the recent research process of Ga_2O_3 based field effect transistors. Furthermore, various structures of FETs have been summarized and compared, and the potential of Ga_2O_3 is preliminary revealed. Finally, the prospect of the Ga_2O_3 based FET for power electronics application is analyzed.     

铁电材料Bi4Ti3O12及应用

叙述了Ｂｉ４Ｔｉ３Ｏ１２材料的结构、性质和制备方法，并对Ｂｉ４Ｔｉ３Ｏ１２铁电薄膜的研究现状和应用前景作了简单分析。     

PZT铁电薄膜介电性能测试研究

运用数字锁相技术研究了Pb(Zr,Ti)O_3(PZT)铁电薄膜的介电性能测试技术,随着薄膜微图形化尺寸的缩小,电路寄生参数的影响将逐渐变大并成为主导因素,从而严重影响薄膜介电性能测试的准确性.通过补偿方法,消除了电路寄生参数的影响,准确测量了薄膜的介电常数.通过对溶胶-凝胶制备的PZT薄膜样品的介电性能测试表明,上述补偿法可满足PZT铁电薄膜制备技术及微机电系统中器件设计对PZT微图形性能测试的要求.     

Structural and electrical characteristics of lanthanum oxide gate dielectric film on GaAs pHEMT technology

This paper investigates the feasibility of using a lanthanum oxide thin film (La_2O_3) with a high dielectric constant as a gate dielectric on GaAs pHEMTs to reduce gate leakage current and improve the gate to drain breakdown voltage relative to the conventional GaAs pHEMT. An E/D mode pHEMT in a single chip was realized by selecting the appropriate La_2O_3 thickness. The thin La_2O_3 film was characterized: its chemical composition and crystalline structure were determined by X-ray photoelectron spectroscopy and X-ray diffraction, respectively.La_2O_3 exhibited good thermal stability after post-deposition annealing at 200, 400 and 600 ℃ because of its high binding-energy (835.6 eV). Experimental results clearly demonstrated that the La_2O_3 thin film was thermally stable.The DC and RF characteristics of Pt/La_2O_3/Ti/Au gate and conventional Pt/Ti/Au gate pHEMTs were examined.The measurements indicated that the transistor with the Pt/La_2O_3/Ti/Au gate had a higher breakdown voltage and lower gate leakage current. Accordingly, the La_2O_3 thin film is a potential high-k material for use as a gate dielectric to improve electrical performance and the thermal effect in high-power applications.     

掺铁TiO2的X-射线衍射和表面光电压谱研究

以溶胶一凝胶法制备了不同掺铁比例的TiO2膜光催化剂，分别以X-射线衍射和场诱导表面光电压谱进行表征。结果表明，在掺铁量小于0．007(Fe／Ti摩尔比)范围内，随着掺铁比的逐渐提高，催化剂粒径逐渐增大，催化剂的带隙宽度加大，光电压响应阈值蓝移，预示着实际应用中催化剂的催化活性的提高。但随着催化剂掺铁比例的进一步提高，Fe2O3，相的出现将导致光催化剂在长波处出现光伏响应，不利于催化剂光活性的提高。     

介质薄膜的制备及其电性能的测试分析

以Al_2O_3薄膜为例,介绍了用电子束蒸发制备介质薄膜的工艺。研究了不同退火条件下Al_2O_3薄膜的电性能,优化出最佳的热处理条件为400℃、氧气气氛中,热处理3 h。并对制得的Al_2O_3薄膜进行了SEM表面和断面分析,结果表明制得的Al_2O_3薄膜较烧结的Al_2O_3基板致密。     

A simple effective method to improve light out-coupling in organic light-emitting diodes by introducing pyramid-based texture structure

This paper showed a very simple method to increase the light extraction of organic light-emitting diodes (OLEDs) by attaching an inverted pyramid texture film to them. The texture film was fabricated by transferring the pyramid-based textured morphology of mono-crystalline silicon surface using a printing process. Compared to the reference device, our results showed a great improvement in the current efficiency (+37.0%) and external quantum efficiency (+36.6%) at a current density of 100 mA/cm². Furthermore, the EL spectrum and CIE coordinates of the OLEDs did hardly vary with the introduction of the texture film and variation of viewing angles, and the OLED with the texture film was proved to be a perfect Lambertian emitter, which suggested that the utilization of this method was a promising approach for the development of OLEDs and could be suggestive conduction to EL lightening and backlight.     

Evaluation of electrical and optical properties of indium tin oxide thin film using chemical mechanical polishing technique

In this study, the optimum process parameters and the influences of their process parameters were investigated for indium tin oxide-chemical mechanical polishing (ITO-CMP) with the sufficient removal rate and the good planarity. And then, the optical property such as transmittance and absorption efficiency, and the electrical characteristics such as sheet resistance, carrier density and Hall mobility were discussed in order to evaluate the possibility of CMP application for the organic light emitting display (OLED) device using an ITO film. Light transmission efficiency and current-voltage characteristics of ITO thin film were improved after CMP process using optimized process parameters compared to that of as-deposited thin film before CMP process.     

A low voltage and small hysteresis C_(60) thin film transistor

Organic thin film transistors with C_(60) as an n-type semiconductor have been fabricated.A tantalum pentoxide(Ta_2O_5)/poly-methylmethacrylate(PMMA) double-layer structured gate dielectric was used.The Ta_2O_5 layer was prepared by using a simple solution-based and economical anodization technique.Our results demonstrate that double gate insulators can combine the advantage of Ta_2O_5 with high dielectric constant and polymer insulator for a better interface with the organic semiconductor.The performanc...     

用XPS法研究硅基硫化锌薄膜

应用X射线光电子能谱(XPS)研究Si基ZnS:Cu,Er薄膜的化学元素组成、分布和价态,认为Cu元素只有少数部分进入晶格中替代Zn2 起激活剂的作用,Er元素在ZnS基质中分布不均匀,且会与氧结合.PL测试发现样品发绿光,主要发光峰出现劈裂,对研究薄膜中的杂质中心、实现Si基发光有参考意义.