共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
Si基Ge异质结构发光器件的研究进展 总被引:2,自引:0,他引:2
近年来,与Si的CMOS工艺相兼容的Ge/Si异质结构发光器件取得很多重要的进展。本文概述了Si基Ge异质结构发光器件的最新成果,如Ge/Si量子点发光二极管、Si衬底上的Ge发光二极管及激光器和Ge/SiGe多量子阱发光二极管,分别描述了这些器件的特点和增强其发光特性的途径。最后展望了Si基Ge异质结构发光器件的发展趋势,指出尽管Si基Ge异质结构发光器件获得了很大的发展,但是器件的发光效率仍然很低,离实用还有一定距离,还需要在材料和器件的结构方面有更多的创新。 相似文献
3.
现有的研究表明,利用光子晶体可以有效提高发光二极管的光提取效率.由于在制造时光子晶体中可能会存在缺陷和错位,本文基于时域有限差分法对光子晶体中的缺陷和错位对发光二极管发光效率的影响进行了研究.数值仿真结果表明,光子晶体中少量缺陷或者微小错位并不会降低发光二极管的光提取效率,其中某些缺陷反而能增强光子晶体发光二极管的光提取效率.本文对其物理机理给出了详细的理论分析,并设计了一种具有缺陷的光于晶体,在未刻蚀到有源层(离有源层20 nm)的情况下,其光提取效率达到了完美光子晶体的1.6倍.通过对这种缺陷光子晶体的空间频谱分析可知,可以通过设计具有特殊空间频谱分布的光子晶体来提高发光二极管的发光效率,这对设计高光提取效率的光子晶体结构和制造高效率的发光二极管有指导意义. 相似文献
4.
近年来,GaN基光子晶体发光二极管(light emitting diode,LED)的研究已经取得了一定的进展,利用光子晶体的光子带隙效应和光栅衍射原理,在LED上制作光子晶体结构将会提高出光效率.本文为了提高AlGaInP系LED的光提取效率,分析了常规LED光提取效率受到限制的原因,将光子晶体结构引入了AlGaInP系LED的器件结构设计,通过理论分析与实验验证,结果显示:光子晶体结构对于提高AlGaInP系LED的光提取效率同样起到了明显的效果,引入光子晶体后,LED的输出光强比常规结构LED平均
关键词:
AlGaInP系LED
光子晶体
光提取效率
光强 相似文献
5.
Si基光互连具有高速度、高带宽、低功耗、可集成等特点, 有望解决集成电路的集成度在日益提高时电互连带来的问题. 在Si基光互连的关键器件中, 除了Si基光源尚未得到解决, 其他器件都已经实现, 因此Si基可集成高效光源具有十分重要的研究意义. 同为IV族元素的Ge 和GeSn因其与Si的可集成性及其独特的能带结构有望成为Si基光电集成回路中的光源. 虽然Ge是间接带隙材料, 但通过引入张应变、n型重掺杂, 或者引入Sn形成GeSn合金等能带工程手段来提高发光效率. 近年来, Si 基IV族发光材料和发光器件有许多重要进展, 本文就Si基Ge, GeSn材料发光研究中的几个关键技术节点——应变工程、掺杂技术、理论模型和器件研究——回顾了近几年国际和国内的研究进展, 并展望了Si基IV族激光器的发展趋势. 相似文献
6.
7.
基于光子晶体技术在一维光子晶体带隙内引入缺陷态模式,并对激光器谐振腔内部电磁场分布和共振波长进行调制,从而将单一波长分裂为双波长输出.最终制备出了一种新的具有双波长光谱输出特性的垂直腔面发射激光器,缺陷层为Al0.8Ga0.2As材料,厚度为5λ/4.所得到的双波长输出光谱具有低吸收损耗、输出波长容易控制及同方向垂直输出特性.同时,通过调整一维光子晶体的折射率差和缺陷层厚度可以有效调谐双波长的间距及输出波段.所设计的双波长垂直腔面发射激光器结构同样
关键词:
垂直腔面发射激光器
光子带隙
双波长 相似文献
8.
利用聚焦离子束刻蚀方法和电子束制版结合干法刻蚀方法制备了二维近红外波段光子晶体,发现两种方法都可以制备出均匀的二维光子晶体,聚焦离子束方法操作简单,电子束制版结合干法刻蚀方法操作步骤复杂.光谱测试表明,利用聚焦离子束方法在有源材料上刻蚀的光子晶体不发光,而电子束制版结合干法刻蚀方法制备的小晶格常数光子晶体即使有些无序,其出光效率也提高到没有光子晶体时的两倍.对两种方法所加工的光子晶体不发光和提高出光效率的机理进行了分析.
关键词:
聚焦离子束
电子束制版
光子晶体
出光效率 相似文献
9.
10.
给出了描述掺杂的一维光子晶体结构缺陷态的变化规律及其空间局域度特性的理论表达式.该式对由具有任意色散关系材料组成的、中间掺杂、两边对称的一维光子晶体结构均成立.通过研究含奇异材料的光子晶体组态发现,当缺陷层材料为右手材料时,光子带隙中缺陷态的频移方向随缺陷层厚度的增大而红移;当缺陷层材料是左手材料时,频移方向刚好相反,表现为蓝移.该缺陷态的空间局域度只与两边对称结构有关.两边对称结构含奇异材料的光子晶体的缺陷态比传统右手材料的结构具有更强的空间局域度. 相似文献
11.
Activation of silicon quantum dots and coupling between the active centre and the defect state of the photonic crystal in a nanolaser 下载免费PDF全文
A new nanolaser concept using silicon quantum dots (QDs) is proposed. The conduction band opened by the quantum confinement effect gives the pumping levels. Localized states in the gap due to some surface bonds on Si QDs can be formed for the activation of emission. An inversion of population can be generated between the localized states and the valence band in a QD fabricated by using a nanosecond pulse laser. Coupling between the active centres formed by localized states and the defect states of the two-dimensional (2D) photonic crystal can be used to select the model in the nanolaser. 相似文献
12.
13.
结合表面缺陷半无限光子晶体Tamm态与多孔硅光学传感机理,在光子晶体表面缺陷腔中引入多孔硅,并利用其高效的承载机制,提出基于多孔硅表面缺陷光子晶体Tamm态的折射率传感结构.在半无限光子晶体中缺陷腔与原来的周期性分层介质结构的界面上存在Tamm态,通过入射角度调制使其在缺陷腔中实现多次全反射,并在缺陷腔中加入吸收介质,使谐振波长在缺陷腔中完成衰荡,从而在反射谱中得到缺陷峰;调整光子晶体参数,使缺陷峰的半高全宽得到优化,提高其品质因数(Q值);在此基础上,根据Goos-H?nchen相位移与谐振波长的关系,建立由待测样本折射率改变所导致的多孔硅表面吸附层有效折射率变化与缺陷峰值波长漂移之间的关系模型,并分析其折射率传感特性.结果表明,此生物传感结构Q值为1429,灵敏度为546.67 nm/RIU,证明了该传感结构的有效性,可为高Q值和高灵敏度折射率传感器的设计提供一定的理论参考. 相似文献
14.
本文简要综述了硅基III-V族量子点激光器的研究进展. 在介绍了量子点激光器的优势和发展后, 重点介绍了近年来硅基、锗基III-V族量子点材料生长上的突破性进展及所带来的器件性能的大幅提高, 如实现了锗基和硅基1.3 μm InAs/GaAs量子点激光器的室温激射, 锗基量子点激光器的阈值电流低至55.2 A/cm2并可达60 ℃以上的连续激射, 通过锗硅虚拟衬底, 在硅基上实现了30 ℃下以16.6 mW的输出功率达到4600 h的激光寿命, 这些突破性的进展为硅基光电子集成打开了新的大门. 相似文献
15.
研究了以InAs量子点为有源区的二维GaAs基光子晶体微腔的设计与制作,测试并分析了室温下微腔的光谱特性.观察到了波长约为1137 nm,谱线半高宽度约为1 nm的尖锐低阶谐振模式发光峰.我们比较了不同刻蚀条件下光子晶体微腔的发光谱线,结果表明空气孔洞截面的垂直度是影响光子晶体微腔发光特性的重要因素之一.通过调节干法刻蚀工艺,改变空气孔半径与晶格常数的比率,可以在较大范围内调节谐振模式发光峰位置,达到谐振模式与量子点发光峰调谐的目的. 相似文献
16.
Yakimov A. I. Bloshkin A. A. Kirienko V. V. Dvurechenskii A. V. Utkin D. E. 《JETP Letters》2021,113(8):498-503
JETP Letters - It has been found that the introduction of layers of Ge/Si quantum dots in a two-dimensional photonic crystal leads to a strong (up to a factor of 5) increase in the photocurrent in... 相似文献
17.
D. Pinotsi J. Miguel Sanchez P. Fallahi A. Badolato A. Imamog̃lu 《Photonics and Nanostructures》2012,10(3):256-262
The system of charge controlled self-assembled quantum dots coupled to high-Q photonic crystal cavity modes is studied. The quantum dots are embedded in a p-i-n diode structure. Different designs of photonic crystal cavities are used, namely H1 and L3 and the Purcell effect is demonstrated. Furthermore, the fine tuning of the H1 cavity design is studied in order to achieve far field emission profiles that result in higher collection efficiency. An increase in the overall signal from the quantum dot when it is coupled to a cavity is observed, due to the Purcell effect and the improved collection efficiency. This together with the deterministic charging of the quantum dot that is demonstrated, can be used for a single electron spin measurement. 相似文献
18.
Modification of the spontaneous emission of quantum dots near the surface of a three-dimensional colloidal photonic crystal 下载免费PDF全文
This paper demonstrates experimentally and numerically that a significant modification of spontaneous emission rate can be achieved near the surface of a three-dimensional photonic crystal.In experiments,semiconductor core-shell quantum dots are intentionally confined in a thin polymer film on which a three-dimensional colloidal photonic crystal is fabricated.The spontaneous emission rate of quantum dots is characterised by conventional and time-resolved photoluminescence (PL) measurements.The modification of the spontaneous emission rate,which is reflected in the change of spectral shape and PL lifetime,is clearly observed.While an obvious increase in the PL lifetime is found at most wavelengths in the band gap,a significant reduction in the PL lifetime by one order of magnitude is observed at the short-wavelength band edge.Numerical simulation reveals a periodic modulation of spontaneous emission rate with decreasing modulation strength when an emitter is moved away from the surface of the photonic crystal.It is supported by the fact that the modification of spontaneous emission rate is not pronounced for quantum dots distributed in a thick polymer film where both enhancement and suppression are present simultaneously.This finding provides a simple and effective way for improving the performance of light emitting devices. 相似文献
19.
A. Hatef 《Optics Communications》2011,284(9):2363-5383
In this paper we have developed a theory for the decay of a quantum dot doped in a two-dimensional metallic photonic crystal consisting of two different metallic pillars in an air background medium. This crystal structure forms a full two-dimensional photonic band gap when the appropriate pillar sizes are chosen. The advantage of using two metals is that one can easily control the density of states and optical properties of these photonic crystals by changing the plasma energies of two metals rather than one. Using the Schrödinger equation method and the photonic density of states, we calculated the linewidth broadening and the spectral function of radiation due to spontaneous emission for two-level quantum dots doped in the system. Our results show that by changing the plasma energies one can control spontaneous emission of quantum dots doped in the metallic photonic crystal. 相似文献
20.
Luz Karime Gil-Herrera Francisco Gallego-Gómez Almudena Torres-Pardo Jose M. González-Calbet Francisco J. Palomares Alvaro Blanco Beatriz H. Juárez Cefe López 《Particle & Particle Systems Characterization》2020,37(1):1900396
Silicon-based materials are needed in cutting-edge technological fields, for which hierarchical porosity and photonic properties help improve performance. In this work, the versatility of several fabrication routes that combine silicon infiltration by chemical vapor deposition (CVD), reactive ion etching (RIE), and carbon calcination, which produce a palette of novel silicon-based material architectures, is demonstrated. Design strategies are discussed and the main features of the processing steps are addressed to provide a variety of new silicon-based materials with high morphological versatility and photonic quality. Three-dimensional hollow carbon opals (HCO) permit control of the porosity of subsequent architectures through the initial silicon infiltration, while open or closed surfaces are achieved primarily as a function of RIE conditions. The composition of derived structures depends on the sequence in which the processes are applied. As a result, pure Si and hybrid C–Si inverse structures can be produced with open or closed spheres in the top layer and with an optional passivation layer. Remarkably, by properly choosing the Si infiltration parameters and the calcination/RIE procedure, final structures are achieved with double-shell spheres. 相似文献