石墨烯量子点/氧化锌纳米线复合提高紫外光传感性能

传统的氧化锌紫外探测器存在光电流小的问题,由于石墨烯具有较高的载流子迁移率,文中采用一种简便的旋涂退火的方法,使得石墨烯量子点在氧化锌纳米线表面复合。利用石墨烯量子点修饰氧化锌纳米线的表面后,制备的氧化锌基紫外光电探测器在5 V偏置电压条件下,在波长为365 nm、功率为1.35 mW/cm2的紫外光照射下,光电流从9.5 μA增加到65 μA,光电流增大了6.8倍,光电流明显提高。这种简单的旋涂退火方法,在有效降低紫外光电探测器加工工艺的同时,提高了探测器的性能,将为下一代可持续绿色发展策略,设计高效率低成本的光电设备提供有益的参考。     

衬底温度及蒸发条件对有机光电探测器性能的影响

为了深入研究p型Si衬底的有机光电探测器的工艺条件对器件光电性能的影响,本文利用Dektak-8型α台阶仪及高分辨率Topometrix Exptorer型原子力显微镜(AFM),对不同衬底温度及蒸发条件下沉积的有机薄膜表面厚度进行了测量;采用拓扑和侧向力接触两种模式,对其表面形貌及其变化规律进行了研究;对制成的光电探测器的光电性能进行了测试分析。结果表明,PTCDA在p-Si(100)表面形成的多晶薄膜呈岛状形态,岛的大小及形貌受制备工艺条件的影响;当衬底温度为50℃、PTCDA的蒸发温度为420℃和蒸发时间为15s时,蒸发薄膜的厚度为135nm;测得器件的最大光电流为92μA,暗电流为7nA。实现了衬底温度及蒸发条件的最佳化。     

化学气相沉积法制备低镁含量的MgxZn1-xO纳米线紫外光电传感器

针对氧化锌紫外光电传感器对深紫外光探测能力弱的问题,通过镁掺杂氧化锌纳米线的方法调整氧化锌能带,从而提高氧化锌紫外光电传感器对深紫外光的探测灵敏度。通过扫描电子显微镜（SEM）、能谱分析（EDS）、透射电子显微镜（TEM）等表征手段对镁锌氧纳米线进行表征,结果表明成功制备镁锌氧纳米线。通过氧化锌纳米线探测器和镁掺杂氧化锌纳米线探测器对254 nm的深紫外进行对比测试,测试结果显示镁掺杂氧化锌探测器对254 nm波长的深紫外光的光响应性能增强,光电流从0.02 μA提高至0.57 μA。通过镁掺杂氧化锌纳米线的方法制备探测器,有效解决氧化锌纳米线探测器对深紫外光探测能力弱的问题,将为深紫外探测器的设计及制备方法提供有益的参考。     

石墨烯/硅异质结光电导型探测器光电响应及噪声

设计并制备了石墨烯/硅异质结光电导型光电探测器,重点分析了光电响应与噪声性能。相比纯硅光电导探测器,石墨烯/硅异质结光电导探测器对635 nm波长激光的净光电流从20μA提升至260μA,与此同时,其1 Hz噪声幅值从3.2×10^-17 A²/Hz增加至2.1×10^-16 A²/Hz。进一步比较两种探测器的相对信噪比(净光电流/1 Hz噪声幅值),发现石墨烯/硅异质结探测器的相对信噪比(1.2×10¹⁸)优于纯硅探测器的(6.3×10¹⁷)。此外,探究了石墨烯条带尺寸对于光电响应及噪声的影响,发现随着石墨烯条带长度的增加,探测器的光电响应与噪声呈下降趋势;随着石墨烯条带宽度的增加,探测器的光电响应与噪声呈上升趋势。进一步比较了不同石墨烯条带长宽比探测器的净光电流与相对信噪比,发现净光电流随着长宽比的增大而减小,而相对信噪比随着长宽比的增大而增加。此外,通过沉积Al₂O₃对探测器的噪声进行了抑制。最后,利用栅压调制...     

一维阵列MSM 4H-SiC紫外光电探测器的研制

采用Ni/Au作为肖特基接触制备了一维阵列MSM 4H-SiC紫外光电探测器,并测量和分析了阵列器件的Ⅰ-Ⅴ、光谱响应特性.结果表明,阵列探测器性能均匀性好,击穿电压均高于100V.阵列中单器件暗电流小,在偏压为20V的时候,最大暗电流均小于5pA(电流密度为5nA/cm2),光电流比暗电流高3个数量级以上.其光谱响应表明,单器件在电压为20V时的响应度约为0.09A/W,比400nm时的比值均大5000倍,说明探测器具有良好的紫外可见比.     

一维阵列MSM 4H-SiC紫外光电探测器的研制

采用Ni/Au作为肖特基接触制备了一维阵列MSM 4H-SiC紫外光电探测器,并测量和分析了阵列器件的Ⅰ-Ⅴ、光谱响应特性.结果表明,阵列探测器性能均匀性好,击穿电压均高于100V.阵列中单器件暗电流小,在偏压为20V的时候,最大暗电流均小于5pA(电流密度为5nA/cm2),光电流比暗电流高3个数量级以上.其光谱响应表明,单器件在电压为20V时的响应度约为0.09A/W,比400nm时的比值均大5000倍,说明探测器具有良好的紫外可见比.     

AlN光电导X-射线探测研究

使用AlN制备了光电导结构的X-射线探测器,研究了探测器对X-射线强度的响应。探测器具有很小的漏电流,在100V的偏压下小于0.1 nA。光电流测量表明：X-射线强度与探测器的光电流成平方关系,并且在强X-射线照射下,光电流与暗电流之比可达到10。利用ABC模型,对探测器的X-射线强度响应特性进行了分析,给出了很好的物理机制解释。     

无催化剂气相沉积法直接制备用于紫外光检测的氧化锌纳米线网

对于环境检测和高速光通信而言,高性能紫外光电探测器是关键。利用气相沉积法在无催化剂条件下制备氧化锌纳米线网,在纳米线网上直接制备光电器件的性能得到了提高。结果显示,纳米线网光电探测器的光电流为60 A,大约是单根纳米线光电器件光电流的15倍。详细讨论纳米线网光电探测器的响应机制发现,在纳米线网内,纳米线与纳米线之间的结势垒高度决定了纳米线内部载流子的传输。当紫外光照射纳米线网光电探测器时,纳米线与纳米线之间结势磊高度的快速变低,从而提高光电器件的性能。     

SOI近红外Si0.8Ge0.2／Si横向pin探测器的研制

给出了SOI近红外Si0.8Ge0.2／Si横向pin光电探测器的设计和制作过程。对制得的样管进行了典型光电参数的测试。测试结果表明，探测器的响应波长范围为0．4～1．3μm，峰值响应波长在0．93～0．97μm，峰值波长下响应度达0．38μA／μW，与Si光电探测器相比，出现明显的响应波长范围和响应峰值波长红移，光电性能达到了预先的设计目标。     

1.3μm高速PIN光电二极管

综合考虑高速光电探测器的频率特性和响应度,优化设计了GaInAs／InPPIN光电二极管的结构参数,解决了长波长高速光电探测器制作中的关键技术,如高纯、超薄GaInAs／InP材料的液相外延生长、有源区的浅结扩散技术、为降低器件漏电采用的双层钝化膜技术和小光敏面的光耦合技术等,并采用同轴封装结构实现了高速光电探测器的高频封装。研制的GaInAs／InPPIN高速长波长光电探测器的3dB带宽达到20GHz,响应度为0．7A／W,暗电流小于5nA。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.