三势垒共振隧穿结构中极大增强的光生空穴共振隧穿

研究了电子隧穿出射端嵌入1.2 μm厚n型弱掺杂GaAs层的三势垒双阱隧穿结构,观察到了隧穿峰谷比高达36的光生空穴共振隧穿峰.研究证实1.2 μm厚n型弱掺杂GaAs层在光照下产生的大量光生空穴以及空穴隧穿出射端的23 nm宽的量子阱中量子化的空穴能级对空穴隧穿谷电流的限制作用,是导致高峰谷比的光生空穴隧穿现象的主要原因.     

共振隧穿二极管中的电荷积累效应——共振隧穿器件讲座(4)

介绍了共振隧穿二极管(RTD)中电荷积累效应,利用顺序隧穿模型分析了RTD中有电荷积累时器件各部分电压的再分布;并结合电压降局限于双势垒区和遍及整个RTD的两种情况,建立了电荷和电流方程;最后利用电荷积累效应解释了负阻区本征双稳态特性。     

共振隧穿二极管

设计并研制出室温工作的共振隧穿二极管,室温电流峰谷比达到7.6:1,最高振荡频率为54GHz。本文对RTD的设计、研制过程、参数和特性测试进行了系统的分析和说明。     

基于共振隧穿二极管的TSRAM设计

介绍了基于共振隧穿二极管的隧穿静态随机存储器的单元结构和原理.讨论了nMOS,pMOS和CMOS作为单元里的选中管的特点,综合考虑面积和功耗后,发现nMOS是选中管的最佳选择.设计了基于RTD的TSRAM系统结构.模拟显示了这种新型存储器具有高集成度、高速和低功耗的优势.     

基于共振隧穿二极管的TSRAM设计

介绍了基于共振隧穿二极管的隧穿静态随机存储器的单元结构和原理.讨论了n MOS,p MOS和CMOS作为单元里的选中管的特点,综合考虑面积和功耗后,发现n MOS是选中管的最佳选择.设计了基于RTD的TSRAM系统结构.模拟显示了这种新型存储器具有高集成度、高速和低功耗的优势.     

共振隧穿器件及其集成技术发展趋势和最新进展

介绍了共振隧穿器件及其特点,论述了该类器件及其集成技术的发展趋势和最新进展,特别是SiO 2S/iS/iO 2共振隧穿二极管及其集成电路的研制成功是一个突破性的进展。     

共振隧穿二极管型光探测器和光调制器

将共振隧穿二极管(RTD)的核心结构——双势垒系统与光探测器和调制器的原理相结合可构成共振隧穿光探测器和共振隧穿光调制器。这些器件既保持了RTD高频、高速的特点,同时又具备了光探测器和光调制器原有的功能,可用于光电集成电路。介绍了这种具有代表性的RTD型光电器件的工作原理、器件结构、制造工艺、器件参数测试等,为此类器件在国内的设计和研制奠定基础。     

共振隧穿二极管研究进展

简要评述共振隧穿二极管（ＲＴＤ）器件研究进展。重点探讨以下问题：为什么ＲＴＤ研究经久不衰？器件理论模型达到何等水平？器件特性、结构和材料方面有哪些关键？围绕这些问题,介绍了有关基本概念,对ＲＴＤ器件物理模型和特性近来的研究成果和前景进行了分析,并提要性地和同类的其它量子器件作了比较。     

倍增型共振隧穿弱光探测器的噪声性能研究

对倍增型共振隧穿弱光探测器(RTDPD,resonant tunneling diode as photodetector)的噪声性能 进行研究。设计了具有倍增区的RTDPD结构。对探测器电流-电压(I-V) 特性的模拟发现,加入倍增区 以后探测器的光电流和暗电流均被放大,其峰值电流增大了1.7倍。 对RTDPD的噪声分布模拟发 现,1/f噪声比散粒噪声和热噪声高出10 个数量级左右。对倍增 区的电场强度和过剩噪声因子进行了模拟, 并计算了过剩噪声的功率谱密度。分析了倍增型RTDPD的总噪声,并对有、无倍增区时RTDPD 的噪声等 效功率进行了计算。结果显示,倍增区引入的噪声不仅不会影响探测器有效信号的提取,而 且提高了探测器响应弱光的能力。     

共振隧穿器件及其集成技术发展趋势和研究热点

在概括了共振隧穿器件及其集成技术的特点和分析了其发展趋势的基础上,给出了该领域当前的研究热点。     

Proposal of an optical modulator based on resonant tunneling andintersubband transitions

We propose and analyze an optical modulator based on intersubband transitions. The absorption is modulated by modulating the carrier density in the ground state of a quantum well (QW). Electrons are injected resonantly into this subband from a QW reservoir subband through a single barrier. When the two states are tuned out of resonance, the electrons are rapidly evacuated by means of the optical field. A waveguide based on surface plasmons is assumed in order to have a high optical mode overlap. Calculations are performed for a cascaded structure with four periods, assuming InGaAs-InIAs QWs. The considered modulator structure operates at λ=6.0 μm and is RC limited to 27 GHz. An extinction ratio of 4 is obtained with a low applied voltage of 0.6 V. At larger applied voltages, the absorption is bistable. Absorption at shorter/longer wavelengths can be obtained by using materials with a larger/smaller conduction band offset. We also assess resonant tunneling from a 2-D electron gas reservoir into an array of quantum dots and compare it to the 2-D-2-D tunneling resonance     

Waveguide polarizer based on resonant tunneling

A novel and highly efficient waveguide polarizer which is based on the phenomenon of resonant tunneling is proposed. Designs for both transverse-electric (TE) and transverse-magnetic (TM) pass polarizers based on this principle are suggested, and it is shown that with such a device it is possible to achieve TM mode loss greater than 80 dB/mm and TE mode loss less than 0.5 dB/mm for the TE pass polarizer, and TE mode loss of 24 dB/mm with a TM mode loss less than 0.8 dB/mm for the TM pass polarizer     

一种基于光学隧穿效应的新型拾音器方案探索

为了探索新型高灵敏度光电拾音器技术方案,基于光学隧穿效应研究,将声压变化转换为全反射棱镜中全反射面与摆片光学面之间的光学隧穿距离变化,从而改变光束在棱镜全反面处的反射（透射）损耗,通过直接测量反射（透射）光的功率变化,实现拾音器基本功能。利用半导体激光器和直角全反射棱镜搭建了一套简易的原理验证实验系统,并利用该系统对三角波信号驱动进行了实验。结果表明,反射光功率会随着三角波信号的改变而改变,光功率改变达到5.6%;由声音引起的玻璃振膜距离变化也可改变输出光功率,并被检测出来。初步验证了该方案的可行性。     

Rashba effect resonant tunneling spin filters

We propose an InAs/GaSb/AlSb-based asymmetric resonant interband tunneling diode (a-RITD) as a spin filter. The device exploits the Rashba effect to achieve spin polarization under zero magnetic field using nonmagnetic III-V semiconductor heterostructures. We discuss the basic principles of the interband tunneling spin filter, and present modeling results that demonstrate its advantage. We also propose an implementation procedure for realizing device structure.     

An exclusive-nor based on resonant interband tunneling FET's

We have proposed and demonstrated an XNOR device based on the negative differential resistance in a resonant interband tunneling diode and the current control capabilities of field effect transistors. DC and timing measurements have confirmed the operations of the device. Simulations and discussions will be presented     

Design of nanopipelined adder based on resonant tunneling diode

Due to the negative differential resistance exhibited by resonant tunneling diode (RTD), RTD is suited to implement the threshold gates and increases the functionality of a single gate. Recently, multi-threshold threshold gates (MTTGs) and generalized threshold gates (GTGs) have been proposed, which extend the circuit applications of RTDs. In this paper, a new RTD full adder structure with three logic modules is proposed. Based on this structure, four different adders are built with the combination of different module circuits based on MTTG and GTG. From the simulation results, one of the proposed circuits with GTG structure, namely FA_GG, has the best performance, which reduces 27.7–45.9% power-delay product value in comparison with the previous designs.     

Multibit resonant tunneling diode SRAM cell based on slew-rateaddressing

We propose and demonstrate a resonant-tunneling diode (RTD) based memory cell in which N bits are stored in a series combination of N RTDs without internal node contacts. The slew rate of an applied voltage signal determines the circuit switching dynamics and allows addressing of the bits. We verify slew rate dependent switching order of up to four series RTDs experimentally and through SPICE simulation incorporating a physics-based RTD model. The new addressing scheme allows N bits to be stored in a stack of N vertically integrated RTDs compared to log₂ (N) bits in previous demonstrations. We demonstrate a two-bit two-RTD static memory cell based on the new method     

A multiple-state memory cell based on the resonant tunneling diode

The device consists primarily of several molecular-beam-epitaxy (MBE-) grown GaAs/(AlGa)As resonant tunneling diodes connected in parallel. This device exhibits multiple peaks in the I-V characteristic. When a load resistor is connected, the circuit can be operated in a multiple stable mode. With this concept, implementation of three-state and four-state memory cells are made. In the three-state case the operating points at voltages V₀=0.27 V , V₁=0.42 V, and V₂=0.53 V represent the logic levels 0, 1, and 2. Similarly for the four-state memory cell the logic levels voltages are V₀=0.35 V, V₁=0.42 V, V₂=0.54 V, and V ₃=0.59 V. A suggestion of an integrated device structure using this concept is also presented     

QDRTD单光子探测技术

量子信息技术的发展对单光子探测器提出了更高的性能要求,新型的量子点单光子探测器展现出了很好的性能和发展潜力。研究了一种基于量子点共振隧道二极管(QDRTD)的单光子探测器,介绍了QDRTD的基本结构和原理,重点对其内部电子传输特性和I-V特性进行了分析,并进行了结构优化,可满足单光子探测中多种波长选择的需求,为QDRTD多波长单光子探测的光子响应特性、探测效能等研究奠定了基础。同时,分析结果表明:QDRTD单光子探测器在光子响应、暗电流、波长选择等多个方面都具备很好的特性,具有广阔的应用前景。     

Integration of a resonant tunneling diode and an optical communications laser

We report on the first integration of a resonant tunneling diode and an optical communications laser operating at around 1.5 /spl mu/m. We demonstrate its low-frequency bistable operation and model its electrical characteristics.