半导体量子点激光器的发展

本文综述了半导体量子点激光器的发展和研究现状，并简单介绍了量子点材料的自组装生长，量子点在其他光电子器件上的应用及其发展趋势。     

量子点及其量子点激光器

本文介绍了零维量子阱结构的量子点生长以及使用这种量子点制作量子点激光器的研究现状。     

量子点及其量子点激光器

本介绍了零维量子阱结构的量子点生长以及使用这种量子点制作量子点激光器的研究现状。     

量子点激光器

本文介绍了新型量子点激光器的概念。量子点激光器的制造技术及量子点激光器的性能。最后指出了量子点激光器的发展趋势。     

量子点激光器

主要介绍了量子点激光器的产生、量子点的生长制作、激光器基本结构和性能、最新进展和未来发展要解决的问题。     

量子点激光器研究进展综述

本文综述了量子点激光器的研究进展。介绍了量子点激光器的结构原理、生长及其优化；对量子点激光器光电特性从实验和建立模型进行描述；给出以速率方程描述的量子点激光器的动态特性如光增益均匀展宽、激射光谱控制、激发态迁移等；最后展望了量子点激光器的研究方向。     

生长停顿对量子点激光器的影响

在ＩｎＡｓ自组织量子点的ＧａＡｓ覆盖层中引入生长停顿,将这种量子点结构作激光器的有源区,与不引入生长停顿的量子点激光器进行对比后发现：生长停顿可以降低激光器的阈值电流,提高其特征温度,改善激光波长的温度稳定性。简单的分析表明,量子点中的能带填充效应影响了激光波长的温度特性。     

InAs/GaAs量子点材料和激光器

介绍了近年来长波长InAsG/aAs量子点材料的生长、结构性质和量子点激光器的研究进展。     

InAs/GaAs自组织量子点激发态的激射

将覆盖层引入生长停顿的量子点结构作为激光器有源区来研究量子点激光器受激发射机制 .由于强烈的能带填充效应 ,光致发光谱和电致发光谱中观察到对应于量子点激发态跃迁的谱峰 ,大激发时其强度超过基态跃迁对应的谱峰 .最后激发态跃迁达到阈值条件 ,激射能量比结构相似但不含量子点的激光器低 ,表明量子点激光器中首先实现受激发射是量子点的激发态     

InAs/GaAs自组织量子点激发态的激射

将覆盖层引入生长停顿的量子点结构作为激光器有源区来研究量子点激光器受激发射机制．由于强烈的能带填充效应, 光致发光谱和电致发光谱中观察到对应于量子点激发态跃迁的谱峰,大激发时其强度超过基态跃迁对应的谱峰．最后激发态跃迁达到阈值条件, 激射能量比结构相似但不含量子点的激光器低,表明量子点激光器中首先实现受激发射是量子点的激发态．     

Yttrium silicide formation and its contact properties on Si(1 0 0)

Yttrium silicide formation and its contact properties on Si(1 0 0) have been studied in this paper. By evaporating a yttrium metal layer onto Si(1 0 0) wafer in conventional vacuum condition and rapid thermal annealing, we found that YSi_2-x begins to form at 350 °C, and is stable to 950 °C. Atomic force microscopy characterization shows the pinholes formation in the formed YSi_2-x film. By current-voltage measurement, the Schottky barrier height (SBH) of YSi_2-x diode on p-type Si(1 0 0) was shown to be between 0.63 and 0.69 eV for annealing temperature from 500 to 900 °C. By low temperature current-voltage measurement, the SBH of YSi_2-x diode on n-type Si(1 0 0) was directly measured and shown to be 0.46, 0.37, 0.32 eV for annealing temperature of 500, 600, and 900 °C, respectively, and possibly even lower for annealing at 700 or 800 °C.     

一种新颖的HgCdTe光伏探测器R0和Cd测量方法

把碲镉汞(HgCdTe)光伏探测器的零偏压结电阻尺.和结电容Cd的交流测试法与124A型锁相放大器的特点结合起来,提出了一种新颖的R0和Cd测量方法.该方法简单易行,而且能准确测量出高阻(R0≥1kQ)HgCdTe光伏探测器的零偏压结电阻R0、结电容Cd、响应时间τ面阻抗(R0A)等参数,并采用标准探测器估算出该系统的...     

NiSi contact metallization using electroless Ni deposition on Pd-activated self-assembled monolayer (SAM) on p-type Si(1 0 0)

In this paper we describe a method to form NiSi contacts using electroless plating of Nickel or Ni alloy on Pd activated self-assembled monolayer (SAM) on p-type Si(1 0 0). Such method allows uniform deposition of very thin, <30 nm, Ni or Ni alloy films. Clean, oxide free, Si substrate was covered with aminopropyltriethoxysilane (APTES) self-assembled monolayer. The surface was activated with Pd-citrate solution followed by electroless plating. The samples were annealed for 1 h in vacuum (∼10⁻⁶ Torr) forming the silicide layer. The annealing temperatures were 400 °C for NiP alloy and 500 °C for NiPW alloy. X-ray diffraction (XRD) measurement confirmed the presence of NiSi phase after annealing. The silicides material properties were characterized using secondary electron microscopy (SEM) analysis, X-ray diffraction (XRD) and X-ray photon spectroscopy (XPS) profiling. The results are reported and summarized.     

Heterodyne frequency measurements on the 12°0-00°0 band of OCS

Heterodyne frequency measurements have been made on the 12°0-00°0 band of carbonyl sulfide in the wavenumber range from 1866 to 1915 cm^?1. Frequency measurement techniques reported earlier are used to measure the OCS absorption lines by means of a tunable diode laser, a CO laser local oscillator, and two CO₂ lasers used as secondary frequency standards. A table of calculated absorption frequencies is given for OCS from 1866 to 1919 cm^?1.     

基于平滑l_0范数的压缩感知近场声全息方法

传统平面近场声全息(CPNAH)是一类典型的不适定问题,采用波数域滤波或Tikhonov正则化等方法都无法彻底解决,因此,提出一种基于平滑l_0范数的压缩感知平面近场声全息法(SL0-CS-PNAH)。根据全息面上测量声压的特点,采用symlets8小波函数构建正交小波变换矩阵,将其作为重建面质点法向振速的稀疏基。将CPNAH中使用的瑞利(Rayleigh)第一积分公式离散化,确定SL0-CS-PNAH中满足约束等距原则的测量矩阵,设置合适的压缩比,利用测量矩阵对稀疏信号进行压缩采样。在由感知矩阵、全息面测量声压和稀疏向量共同构成的约束条件下,建立稀疏向量的最小l_0范数优化模型,采用平滑l_0范数重建算法求解此模型下的最优化问题,得到质点法向振速的最优稀疏解,再将最优稀疏解和稀疏基相乘恢复重建面质点法向振速。在数值仿真实验中,将测量点由64×64减少到32×64的情况下将传统CPNAH、基于正交匹配追踪算法的压缩感知近场声全息(OMPCS-PNAH)、基于子空间追踪算法的压缩感知近场声全息(SP-CS-PNAH)和SL0-CS-PNAH进行比较。实验结果表明,在相同采样率和压缩比条件下,采用SL0-CS-PNAH的声场重建质量较好且重建效率较高。     

A 7-bit 500 kS/s 1 V micro-power SAR A/D converter for pixel systems

The design and measurement results of a micro-power successive approximation charge redistribution ADC implemented in CMOS 180 nm technology are presented. The project has been optimized for very low area occupancy in order to utilize it in multichannel neural signal recording pixel systems for future application. The design has been fabricated, experimentally characterized and it exhibits good performance, especially from the silicon area occupation point of view. The presented converter achieves 500 kS/s sampling rate with ENOB of 6.54 at 4.45 μW and occupies only 90 μm×95 μm of silicon area.     

1394-VXI零槽控制器模件设计和实现

阐述了基于IEEE1394总线的VXI零槽扩展基器件的基本原理,给出了1394／VXI零槽控制器的逻辑结构、软硬件设计和实现过程。试验结果表明该系统可以稳定地工作,能够和HP系列的VXI总线设备进行互连和集成。     

基于FM0记忆辅助特性的RFID标签碰撞检测

为实现两个射频识别(RFID)碰撞标签信息的检测和分离，提出一种利用Gen2标准中FM0标签编码固有记忆特性的检测方法。通过对FM0比特编码特点和碰撞标签信息的无记忆检测分析，得到基于单个比特持续时间的无记忆检测方法的条件错误概率和单个标签信息检测的误码率；然后利用单个FM0比特编码需要前一比特的“记忆”特性，得到对应于前一比特的一对测量值和对应于下一比特的一对测量值，进而得到碰撞标签信息的1比特记忆辅助检测时的条件错误概率和误码率性能；并对在帧Aloha媒质接入方案中采用提出的检测方法时的N个标签群的总延迟减少性能进行了分析。仿真实验结果表明，提出的1比特记忆辅助检测方法，相比于无记忆检测具有更好的误码率性能，且能减少标签群接入时的总延迟。     

非线性参量对扬声器谐振频率f0的影响

讨论了扬声器谐振频率f0测试的不确定性,对f0测试标准进行了解读,从非线性角度分析了扬声器谐振频率波动的根本原因,并给出了正确的测试方法。     

介质加载圆柱谐振腔中TM0模的RMM分析

对介质加载圆柱谐振腔进行严格分析是进行微波电路设计和微波介电测试的基础。根据平行板多层介质径向波导的本征模分析，采用径向模式匹配法获得了介质加载圆柱谐振腔中TM0模的本征方程，在此基础上开发了计算TM0模谐振频率的程序，对特定结构进行了计算，结果与参考文献一致。