AIN膜及其在半导体光电器件中的应用

本文报道溅射AlN膜及其应用于半导体光电器件的实验研究结果。测定了不同条件下溅射的AlN膜厚度、淀积速率、折射率和击穿电场强度。首次用AlN膜做器件的端面保护和减反射膜以及表面钝化膜均获得成功。几种常用介质膜的实验数据对比分析表明AlN膜在半导体光电器件领域将有广阔应用前景。     

Pt/Si界面化学键性质的研究

在超高真空系统中,超薄层 Pt淀积膜原位蒸发在原子清洁的 Si(111)表面上形成 Pt/Si界面.利用光电子谱技术(XPS和UPS)研究了Pt/Si 界面的化学性质.测量了Si2p和Pt 4f芯能级和价带电子态,并着重研究这些芯能级及电子态在低覆盖度时的变化.由 Si(2p)峰的强度随 Pt 覆盖度的变化可以清楚证明:在 300 K下淀积亚单原子层至数个单原子层 Pt的 Pt/Si(111)界面发生强烈混合作用,其原子组伤是缓变的.由于Si原子周围的 Pt原子数不断增加,所以 Pt 4f芯能级化学位移随 Pt原子覆盖度的增加而逐步减小,而Si 2p芯能级化学位移则逐步增大.同时,Pt 4f峰的线形也产生明显变化,对称性增加;Si 2p峰的线形则对称性降低.淀积亚单原子层至数单原子层Pt的UPS谱,主要显示两个峰:-4.2eV(A峰),-6.0eV(B峰).A峰随着覆盖度的增加移向费米能边,而B峰则保持不变.这说明Ptd-Sip键合不受周围Pt原子增加的影响.利用Pt/Si界面Pt原子向Si原子的间隙扩散模型讨论了所观察到的结果.     

含C60聚合物薄膜的制备及其光电特性

采用ＰＥＣＶＤ技术，分别在不同衬底上淀积了含Ｃ７０聚合物薄膜材料，对所淀积的薄膜材料进行了紫外可见光谱，质谱和表面光电压谱的分析，对异质结光伏性和薄膜表面横向光电压进行了测量，得到了具有应用前景的可喜效果。     

淀积条件对化学淀积PbS光电导特性的影响

本文研究了淀积时间和淀积溶液中氢氧化物和铅离子浓度对于化学淀积PbS膜光电导特性的影响。从时间常数、噪声和电阻的测量可以看出,淀积条件决定着俘获中心的数量以及载流子密度。在制备的条件下,俘获中心和PbS晶格中淀积的过量铅原子有关。     

稀释气体对GD淀积a-Si:H膜的光电性质的影响

本文研究了用氦和氢作为硅烷的稀释气体对GD淀积的a-Si:H膜的光电性质的影响.测量了用两种稀释气体GD淀积的a-Si:H膜的光电导、光学带隙、红外吸收和光致发光.实验结果表明用氦稀释硅烷GD淀积的a-Si:H膜有更低的缺陷态密度,是一种廉价薄膜太阳电池可供选择的基本材料.     

MOXtronics制造出ZnO光电二极管与P型FET

ZnO及其合金基器件开发商MOXtronics与密苏里大学、南韩首尔国际大学等联手制造出ZnO紫外光电二极管和P型FET。这个研究小组称,上述成果表明,ZnO可用来制造宽频带的器件,并且表明,砷是形成P型ZnO的一种良好掺杂剂。ZnO器件之所以受到关注,是因为它们适合用于苛刻的环境,如核反应堆与太空。该材料的抗辐射性高于Si、GaAs、SiC和GaN。这种ZnO光电二极管和FET是用混合束淀积(HBD)的。混合束淀积是一门可提供固相、汽相和气源材料的晶体生长技术。MOXtronic公司表示,之所以使用混合束淀积,是因为常规生长方法如MBE和CVD不适宜…     

半导体材料的激光化学气相淀积

半导体材料的激光化学气相淀积即光CVD(Pheto-Chemical Vaporous Deposition)是近几年发展起来的低温淀积技术。它具有淀积温度低、薄膜均匀、光电性能优良、选择性好和易于控制等特点。本文着重于介绍光CVD的原理、特点、工艺、设备及在氢化非晶硅、二氧化硅、氮化硅及其它半导体材料中的应用。     

PMMA-CsPbBr3薄膜的结构及光电特性

CsPbBr3是一种直接带隙宽禁带半导体,具有优异的光电性能。采用喷雾法制备了不同质量分数的聚甲基丙烯酸甲酯(PMMA)-CsPbBr3薄膜。利用原子力显微镜(AFM)和扫描电子显微镜(SEM)研究了PMMA质量分数对PMMA-CsPbBr3薄膜表面形貌的影响,利用X射线衍射(XRD)对其结构进行了表征,同时还测量了材料的透射率并给出了光致发光(PL)图像,最后制成了PMMA-CsPbBr3/Au异质结型光电探测器,研究了它们的光电特性。结果表明:掺入PMMA可以显著改善PMMA-CsPbBr3薄膜表面形貌,随着加入PMMA的质量分数的增大,CsPbBr3薄膜的表面粗糙度明显下降,均方根粗糙度从311 nm降低到69.2 nm;同时PMMACsPbBr3薄膜是择优取向的;与纯CsPbBr3薄膜相比,PMMA-CsPbBr3薄膜的透射率明显增加。通过研究制备的PMMA-CsPbBr3/Au异质结型光电探测器的I-V特性,发现随着PMMA的加入,异质结器件的暗电流降低,同时其光电流密度和稳定性增加。     

fmax为30.8GHz的超薄Al2O3绝缘栅GaN MOS-HEMT器件

报道了一种利用原子层淀积(ALD)生长超薄(3.5nm)Al2O3为栅介质的高性能AlGaN/GaN金属氧化物半导体高电子迁移率晶体管(MOS-HEMT).新型AlGaN/GaN MOS-HEMT器件栅长1μm,栅宽120μm,栅压为 3.0V时最大饱和输出电流达到720mA/mm,最大跨导达到130mS/mm,开启电压保持在-5.0V,特征频率和最高振荡频率分别为10.1和30.8GHz.     

不同介质膜的InP MIS结构界面陷阱的研究

对经 PECVD(Plasma Enhanced Chemical Vapor Deposition)生长的不同介质膜 InPMIS结构样品的界而陷阶进行了研究.样品介质膜的生长是在特定实验条件下进行.分别利用C-V(Capacitance-Voltage)和 DLTS(Deep Level Transient Spectroscopy)技术进行研究.结果表明,在介质膜和InP之间InP 一侧有若干界面陷阱存在,获得了与界面陷阱有关的深能级参数.这些陷阱的来源可能是:(1)介质膜淀积过程中InP表面部分P原子挥发造成的P空位;(2)InP衬底材料中的原生缺陷;(3)介质膜淀积过程中等离子体引进的有关辐照损伤.     

BR0-代数中MT理想的扩展及素MT理想的存在性

BR₀-代数是一类重要的基础逻辑代数,其中著名的MV代数和R₀-代数均是BR₀-代数的特款,因而对BR₀-代数研究结果具有普遍的实用性.首先,通过BR₀-代数中极大并-理想的存在性证明了BR₀-代数中素并-理想的存在性;其次,利用对偶范畴的思想方法和MP滤子的特征,在BR₀-代数中提出了MT理想,极大MT理想,素MT理想等概念,讨论了它们的基本性质及相互关系,并通过素并-理想构造性的证明了素MT理想的存在性;最后,在非退化的BR₀-代数中证明了任何一个真MT理想可以扩展为一个极大素MT理想.本文的工作是对BR₀-代数研究内容和方法的有益补充.     

Flexible solar cells based on PCBM/P3HT heterojunction

[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) / poly (3-hexylthiophene) (P3HT) heterojunction has not only the absorption in ultraviolet light for PCBM,but also the absorption in visible light for P3HT, which widens the incident light harvest range, improving the photoelectrical response of hybrid solar cell effectively.Using conducting polymers blend heterojunetion consisting of C60 derivatives PCBM and P3HT as charge carrier transferring medium to replace I3-/I- redox electrolyte and dye, a novel flexible solar cell was fabricated in this study.The influence of PCBM/P3HT mass ratio on the photovoltaic performance of the solar cell was also studied.flexible solar cell achieved a light-to-electric energy conversion efficiency of 1.04%, an open circuit voltage fill factor (FF) of 0.46.     

Influence of Phosphorus Content on the Interfacial Microstructure Between Sn–3.5Ag Solder and Electroless Ni–P Metallization on Cu Substrate

Under bump metallization (UBM), which usually consists of a few thin metallic layers, provides good solderable surface while protecting the underlying metallization from reacting with solder. Electroless nickel (Ni-P) with a thin layer of immersion gold has been considered as one of the promising candidates for under bump and substrate metallizations. However, the presence of P in electroless Ni-P causes more complicated interfacial reactions with solder than pure Ni. The amount of P in the Ni-P layer affects the soldering reaction in terms of microstructure and reaction kinetics. In this paper, influence of P content on the interfacial microstructure between Sn-3.5Ag solder and electroless Ni-P metallization on Cu substrate has been investigated. Electroless Ni-P layers of three different P contents (6.1, 8.8, and 12.3 wt.%) with the same thickness were plated on Cu substrate. Multilayered samples with Sn-3.5Ag/Ni-P/Cu stack were then prepared and subjected to multiple reflows. Various types of interfacial compounds (IFCs) such as Ni₃Sn₄, Ni₃P, Ni-Sn-P, Cu-Sn, and Ni-Cu-Sn formed depending upon the number of reflows. Ni₃Sn₄ intermetallic compound that formed in the low P sample was found to be more stable, whereas, Ni₃Sn₄ that formed in the medium and high P samples mostly spalled off into the molten solder during reflow. The Ni ₃Sn₄ spallation was found responsible for thicker Cu-Sn and Ni-Cu-Sn intermetallics in the medium and high P samples as compared to that of low P sample. Explanation for the observed interfacial microstructure is proposed in the paper in detail     

Pt/YSZ电极结构形貌的表征

根据YSZ型氧传感器中O在电极表面的吸附、扩散以及Pt/YSZ界面O(Pt电极中)/O2(YSZ中)的传递的机理,提出了一种对Pt /YSZ电极界面进行定量表征的模型。用此模型对不同烧结温度下的电极形貌Pt/空气/ YSZ三相界面长度进行了定量表征,同时,采用复阻抗测试技术和氧传感器响应测试技术对表征结果的合理性进行了验证。理论推算和试验结果都表明:采用1 000℃,1 h烧结的电极形貌具有最佳的电化学性能。     

基于正则FI代数的MT理想及其应用

 本文基于经典代数的角度对正则FI代数进行了再研究.首先,在正则FI代数中通过蕴涵算子提出了MT理想的概念,讨论了正则FI代数中MT理想与同余关系的联系;其次,在正则FI代数中引入素MT理想的概念,并以素MT理想为工具给出了正则FI代数的条件嵌入定理;最后,通过以蕴涵算子表示的隐式余三角模对MT理想的特征进行了描述,并通过特征定理给出了正则FI代数中MT理想的生成方法.     

Size Effects of Platinum Nanoparticles in the Photocatalytic Hydrogen Production Over 3D Mesoporous Networks of CdS and Pt Nanojunctions

Catalysts for the photogeneration of hydrogen from water are key for realizing solar energy conversion. Despite tremendous efforts, developing hydrogen evolution catalysts with high activity and long‐term stability remains a daunting challenge. Herein, the design and fabrication of mesoporous Pt‐decorated CdS nanocrystal assemblies (NCAs) are reported, and their excellent performance for the photocatalytic hydrogen production is demonstrated. These materials comprise varying particle size of Pt (ranging from 1.8 to 3.3 nm) and exhibit 3D nanoscale pore structure within the assembled network. Photocatalytic measurements coupled with UV–vis/NIR optical absorption, photoluminescence, and electrochemical impedance spectroscopy studies suggest that the performance enhancement of these catalytic systems arises from the efficient hole transport at the CdS/electrolyte interface and interparticle Pt/CdS electron‐transfer process as a result of the deposition of Pt. It is found that the Pt‐CdS NCAs catalyst at 5 wt% Pt loading content exerts a 1.2 mmol h^?1 H₂‐evolution rate under visible‐light irradiation (λ ≥ 420 nm) with an apparent quantum yield of over 70% at wavelength λ = 420 nm in alkaline solution (5 m NaOH), using ethanol (10% v/v) as sacrificial agent. This activity far exceeds those of the single CdS and binary noble metal/CdS systems, demonstrating the potential for practical photocatalytic hydrogen production.     

数字交换芯片MT90826及其应用

MT90826芯片是MITEL公司生产的大容量数字交换器件,单片可实现4096×4096通道的无阻塞交换,可编程建立在每一个通道基础上、附带不同通过延时的时隙交换,利用该器件的组合可构成更大容量的交换网络或交叉连接矩阵。该器件可有效解决传统交换机采用多个存储器及控制集成电路所构成的交换网络系统存在的生产成本高、调试困难、稳定性差等问题。文章介绍了MT90826芯片的内部结构、原理及时序关系,并给出了控制软件设计,其编程思路可拓展到MITEL公司同系列的其他数字交换芯片。     

Tuning and Enhancing Photoluminescence of Light‐Emitting Polymer Nanotubes through Electron‐Beam Irradiation

A new method for the tuning and enhancing photoluminescence (PL) characteristics of light emitting poly (3‐methylthiopnehe) (P3MT) nanotubes through E‐beam irradiation under atmospheric environments is reported. An E‐beam generated from a linear electron accelerator (1 MeV, 1.6 × 10¹³–8.0 × 10¹⁶ electrons cm^–2) is irradiated onto P3MT nanotubes including an Al₂O₃ template. From laser confocal microscope (LCM) PL experiments, significant enhancements in the PL intensity—up to about 90 times of an isolated single strand of the E‐beam irradiated P3MT nanotubes—are observed. The luminescent color of the P3MT nanotubes changes from green to red color depending on the variation of E‐beam dosage. These results might originate from the de‐doping effect and the conformational modification through E‐beam irradiations. Conformational changes of the E‐beam irradiated P3MT nanotubes are confirmed by LCM single Raman and ultraviolet‐visible (UV/Vis) absorption spectra. From UV/Vis absorption spectra, it is observed that the π–π* transition peak and the doping induced bipolaron peaks of the P3MT nanotubes dramatically vary with E‐beam irradiating conditions.     

金属硫蛋白(MT)分离纯化技术进展

较全面地总结了近几年来金属硫蛋白最常见的分离纯化方法 ,并较详细地介绍了磁法分离纯化、芯片检测等新技术     

Multifunctional π-conjugated poly (3-methylthiophene) nanotubes for optoelectronic and field emissive devices

Multifunctional properties of nanomaterials becomes a hot topic in nano research for the development of multifunctional devices, because modern devices need multifunctional platform for the high efficient plural performance on a single device. Here, we introduce a multifunctional π-conjugated poly (3-methylthiophene) (P3MT) nanotube (NT), showing controllable optical and electrical properties through the control of doping level. P3MT NTs were electrochemically synthesized in the low temperature (−40 °C) on the nanoporous template. The change of doping level by post cyclic voltammetry (CV) treatment on the P3MT lead the variance of polaron/bipolaron band, resulting into the drastic change of ultraviolet-visible absorption and photoluminescence properties. While P3MT NTs before CV treatment show an ohmic behavior in the current-voltage characteristics, those after CV treatment show high photocurrent. From the field emission experiment, the P3MT NTs before CV treatment have a relatively low turn-on electric field and stable electron emission property compared to the P3MT NTs after CV treatment. This shows that the π-conjugated polymers should be shed new light on their multifunctionality for the potential application to the multifunctional platform of opto-electronic nanodevices.