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1.
p型量子阱太赫兹振荡器研究 总被引:1,自引:0,他引:1
采用非抛物平衡方程理论研究了直流偏置下 p型量子阱负有效质量 p+ pp+ 二极管电流的时空特性。在适当的掺杂和偏置条件下 ,由于高场畴的形成 ,二极管中将产生太赫兹 (THz,1 THz=1 0 1 2 Hz)电流自振荡。计算了自振荡频率对直流偏置的依赖性 ,提出了设计可调谐 THz振荡源的可能性 相似文献
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针对四阱有源区、一阱注入区及三阱有源设计,采用蒙特卡洛模拟方法研究了共振声子太赫兹量子级联激光器的性能差异。采用傅里叶变换光谱仪及远红外探测器测量了四阱共振声子太赫兹量子级联激光器的低温电光特性。详细讨论了提高太赫兹量子级联激光器发射功率的方案。 相似文献
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通过蒙特卡洛方法研究了基于共振声子散射的太赫兹量子级联激光器中杂质散射对激光器性能的影响.使用单子带静态屏蔽模型来处理电子与杂质的散射过程.发现电子与杂质的散射为电子在有源区中的注入和抽取过程提供了另外一个通道.这一过程可以影响电子在不同子带的占据数以及器件的电流.所以,在考虑基于共振声子散射的太赫兹量子级联激光器中的电子输运过程时,需要包含电子与杂质的散射过程. 相似文献
4.
通过蒙特卡洛方法研究了基于共振声子散射的太赫兹量子级联激光器中杂质散射对激光器性能的影响.使用单子带静态屏蔽模型来处理电子与杂质的散射过程.发现电子与杂质的散射为电子在有源区中的注入和抽取过程提供了另外一个通道.这一过程可以影响电子在不同子带的占据数以及器件的电流.所以,在考虑基于共振声子散射的太赫兹量子级联激光器中的电子输运过程时,需要包含电子与杂质的散射过程. 相似文献
5.
通过蒙特卡洛方法研究了基于共振声子散射的太赫兹量子级联激光器中杂质散射对激光器性能的影响.使用单子带静态屏蔽模型来处理电子与杂质的散射过程.发现电子与杂质的散射为电子在有源区中的注入和抽取过程提供了另外一个通道.这一过程可以影响电子在不同子带的占据数以及器件的电流.所以,在考虑基于共振声子散射的太赫兹量子级联激光器中的电子输运过程时,需要包含电子与杂质的散射过程. 相似文献
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为了获得低阈值连续波工作太赫兹源,采用固源分子束外延技术生长了GaAs/AlGaAs束缚态向连续态跃迁的太赫兹量子级联激光器(QCL)有源区,基于半绝缘-等离子体波导工艺制作了太赫兹量子级联激光器。获得了激光器(腔面未镀高反射膜)的发射光谱和相应的输出特性等性能,其中器件在10 K工作温度、350 mA激励电流下的中心频率为2.93 THz,连续波工作模式的阈值电流密度为156 A/cm2,器件的最大光输出功率为7.84 mW,最高工作温度为62 K。 相似文献
8.
太赫兹量子级联激光器和太赫兹量子阱探测器都是基于子带间电子跃迁的半导体器件,具有体积小、频率可调、响应速度快等优点。其工作波长位于微波波长和红外波长之间,其光谱涵盖了众多气体分子、化合物以及凝聚态物质的频谱特征,在天文观测、公共安全、生物医药等领域中有重大应用前景。近年来,太赫兹量子级联激光器和太赫兹量子阱探测器的性能有了显著提高,其应用也受到关注。回顾了太赫兹量子级联激光器和量子阱探测器的发展历程,简述了其工作原理和器件结构,介绍了器件性能在工作温度、光谱范围等方面的最新进展及其在高分辨光谱、太赫兹成像、无线宽带通信等方面的应用,并在此基础上分析了目前存在的问题和研究热点,对其未来发展进行了展望。 相似文献
9.
主要研究了太赫兹量子阱探测器读出电路中的暗电流抑制模块。首先从理论上分析了太赫兹量子阱探测器产生暗电流和光电流的原理。由于太赫兹量子阱探测器中电子输运行为非常复杂,难以通过理论推导建立精确等效电路模型的解析表达式。通过对太赫兹量子阱探测器的电流电压实验数据进行拟合,提出压控电流源等效电路模型。利用此模型设计读出电路信号源及暗电流抑制模块,结合读出电路进行仿真验证电路模型的准确性。发现与传统暗电流抑制电路相比,压控电流源电路模型能够在器件工作偏压变化时对其暗电流进行精确抑制,提高读出电路性能,因此更适合作为太赫兹量子阱探测器读出电路的暗电流抑制模块。 相似文献
10.
采用系综Monte Carlo(EMC)方法首次对光泵量子阱THz激光器的载流子瞬态动力学进行了分析。提出的器件原型为三能级调制掺杂GaAs/GaxAl(1-x)As系列非对称阶梯量子阱,激射频率为6.1THz。模拟中包括了电子-电子、电子-光学声子和电子-声学声子等散射机制,采用调制掺杂以得到较高电子密度可以忽略电子-电离杂质散射。已报道的研究工作都是在量子阱中掺杂,而对于这种器件原型能否得到电子布居反转,报道的结果也是相互矛盾。器件原型在温度为77K,光泵强度达到一定值时可以得到电子布居反转,所得到的研究结果对相关的实验研究具有一定的指导意义。 相似文献
11.
D. X. Xu G. D. Shen M. Willander J. Knall M. -A. Hasan G. V. Hansson 《Journal of Electronic Materials》1990,19(10):1033-1041
Different Si homojunction and strained Si1-xGex/Si heterojunction diodes and bipolar transistors have been fabricated by Si-MBE. The effect of annealing on Si homojunction
diodes and transistors are studied. It is found that annealing generally improves the Si device performance, such as the ideality
factor and breakdown characteristics. The influence of60Co γ irradiation on the Si1-xGex/Si diode performances are investigated by studying the temperature dependence of their electrical characteristics, and the
results are correlated with the quality of the MBE-films. γ irradiation causes a drop in material conductivity due to the
generation of atom-displacement defects in the whole volume of the wafers and increases the defect density at hetero-interfaces.
The forward I-V curves of Si1-xGex/Si devices may shift towards lower or higher voltages, depending on the film quality and the irradiation dose. The increase
of defect density in strained Si1-xGex/Si films appears to occur easier for the films with lower quality. Electrical measurements and calculations show that the
defect-associated tunneling process is important in current transport for these MBE grown Si homojunction and strained Si1-xGex/Si heterojunction devices, which have initially medium film quality or have been treated by irradiation. 相似文献
12.
M. Peter J. Forker K. Winkler K. H. Bachem J. Wagner 《Journal of Electronic Materials》1995,24(11):1551-1555
Two types of quantum well (QW) structures grown lattice matched on (100) GaAs have been studied. The first type of structure
consists of pseudomorphic GaAsxSb1-x/GaAs (x≤0.3) SQWs which show emission wavelengths longer than those reported for pseudomorphic InyGa1−yAs/GaAs QWs. However, the attractive emission wavelength of 1.3 μm has not been achieved. To reach this goal, a novel type
of bilayer QW (BQW) has been grown consisting of a stack of two adjacent pseudomorphic layers of GaAsxSb1−x and In Ga1-y As embedded between GaAs confinement layers. In this BQW, a type-II heterojunction is formed between GaAsxSb1−x and InyGa1−yAs, resulting in a spatially indirect radiative recombination of electrons and holes at emission wavelengths longer than those
achieved in the GaAsxSb1−x/GaAs and IiyGa1−yAs/GaAs SQWs. The longest 300K emission wavelength observed so far was 1.332 μm. 相似文献
13.
Gaetano Scamarcio Miriam Serena Vitiello Vincenzo Spagnolo 《Journal of Infrared, Millimeter and Terahertz Waves》2013,34(5-6):357-373
We compare the electrical power dependence of the lattice temperature and the electronic temperature of GaAs/AlxGa1-xAs THz quantum cascade lasers (QCLs) with different active region schemes, as extracted by the analysis of microprobe band-to-band photoluminescence experiments. Thermalized non-equilibrium distributions are found in all classes of QCLs. While in the case of bound-to-continuum structures all subbands share the same temperature, the upper laser level of active regions based on the resonant-phonon scheme heats up by ΔT ~ 100 K with respect to lower energy levels. The comparison among samples with different Al mole fractions show that the use of smaller x values leads to larger electronic temperatures. 相似文献
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A newly-developed phosphorus source, tertiarybutylphosphine (TBP), which is much less toxic than PH3, has been used to grow InP and GaAs1-xPx by atmospheric pressure organometallic vapor phase epitaxy (OMVPE). Excellent morphologies are obtained for the growth of
InP between 560 and 630° C for TBP partial pressures larger than 0.5 x 10-3. For the first time, V/III ratios as low as 3 have been used to grow InP epilayers with featureless morphologies at 600°
C. To obtain good morphologies at both lower and higher temperatures, higher TBP partial pressures are necessary. The electron
mobility increases and the electron density decreases as the temperature is increased. The highest room temperature mobilities
and lowest electron densities, obtained at 630° C, are 3800 cm2/V-sec and 3 x 1015 cm-3, respectively. The 10 K photoluminescence spectra of the InP epilayers at higher growth temperatures show no carbon contamination.
Bound excition half widths as low as 3.0 meV have been measured. The use of TBP to replace PH3 in the growth of GaAs1-xPx results in a nearly linear relationship between vapor and solid composition at 610° C,i.e., the P distribution coefficient is nearly unity. This contrasts sharply with the very low P distribution coefficient obtained
using PH3 at such low growth temperatures. 相似文献
16.
F. A. Kish . J. Caracci N. Holonyak K. C. Hsieh J. E. Baker S. A. Maranowski A. R. Sugg J. M. Dallesasse R. M. Fletcher C. P. Kuo T. D. Osentowski M. G. Craford 《Journal of Electronic Materials》1992,21(12):1133-1139
Data are presented demonstrating the formation of native oxides from high Al composition In0.5(AlxGa1-x)0.5P (x≳ 0.9) by simple annealing in a “wet” ambient. The oxidation occurs by reaction of the high Al composition crystal with
H2O vapor (in a N2 carrier gas) at elevated temperatures (≥500° C) and results in stable transparent oxides. Secondary ion mass spectrometry
(SIMS) as well as scanning and transmission electron microscopy (SEM and TEM) are employed to evaluate the oxide properties,
composition, and oxide-semiconductor interface. The properties of native oxides of the In0.5(AlxGa1-x)0.5P system are compared to those of the AlxGa1-xAs system. Possible reaction mechanisms and oxidation kinetics are considered. The In0.5(AlxGa1-x)0.5P native oxide is shown to be of sufficient quality to be employed in the fabrication of stripe-geometry In0.5(AlxGa1-x)0.5P visible-spectrum laser diodes. 相似文献
17.
J. P. André E. P. Menu M. Erman M. H. Meynadier T. Ngo 《Journal of Electronic Materials》1986,15(2):71-74
High quality InP and Ga1-x InxAs layers have been grown on InP substrates using MOVPE growth at atmospheric pressure. Excellent material quality has been obtained using triethylindium and trimethylgallium sources(n = 1.7 1014 cm-3, μ = 106 000 cm2V-1s-1 at 77 K for InP andn = 1 ? 3 1015 cm-3, μ= 75 000 cm2V-1 s-1 at 77 K for Ga1-xInxAs). The InP/Ga1-xInxAs interface width obtained is very small (10 Å). The first PIN diodes grown by the process exhibit excellent characteristics. 相似文献
18.
T. Hsu B. Anthony R. Qian J. Irby D. Kinosky A. Mahajan S. Banerjee C. Magee A. Tasch 《Journal of Electronic Materials》1992,21(1):65-74
Remote plasma-enhanced chemical vapor deposition (RPCVD) is a low temperature growth technique which has been successfully employed inin situ remote hydrogen plasma clean of Si(100) surfaces, silicon homoepitaxy and Si1- xGex heteroepitaxy in the temperature range of 150–450° C. The epitaxial process employs anex situ wet chemical clean, anin situ remote hydrogen plasma clean, followed by a remote argon plasma dissociation of silane and germane to generate the precursors for epitaxial growth. Boron doping concentrations as high as 1021 cm?3 have been achieved in the low temperature epitaxial films by introducing B2H6/He during the growth. The growth rate of epitaxial Si can be varied from 0.4Å/min to 50Å/min by controlling therf power. The wide range of controllable growth rates makes RPCVD an excellent tool for applications ranging from superlattice structures to more conventional Si epitaxy. Auger electron spectroscopy analysis has been employed to confirm the efficacy of this remote hydrogen plasma clean in terms of removing surface contaminants. Reflection high energy electron diffraction and transmission electron microscopy have been utilized to investigate the surface structure in terms of crystallinity and defect generation. Epitaxial Si and Si1-xGex films have been grown by RPCVD with defect densities below the detection limits of TEM (~105 cm-2 or less). The RPCVD process also exploits the hydrogen passivation effect at temperatures below 500° C to minimize the adsorption of C and 0 during growth. Epitaxial Si and Si1-xGex films with low oxygen content (~3 × 1018 cm-3) have been achieved by RPCVD. Silicon and Si/Si1-xGex mesa diodes with boron concentrations ranging from 1017 to 1019 cm-3 in the epitaxial films grown by RPCVD show reasonably good current-voltage characteristics with ideality factors of 1.2-1.3. A Si/Si1-xGex superlattice structure with sharp Ge transitions has been demonstrated by exploiting the low temperature capability of RPCVD.In situ plasma diagnostics using single and double Langmuir probes has been performed to reveal the nature of the RPCVD process. 相似文献
19.
Hung Chi Chou Anas Mazady John Zeller Tariq Manzur Mehdi Anwar 《Journal of Electronic Materials》2013,42(5):882-888
A ZnO/Zn1?x Mg x O-based quantum cascade laser (QCL) is proposed as a candidate for generation of THz radiation at room temperature. The structural and material properties, field dependence of the THz lasing frequency, and generated power are reported for a resonant phonon ZnO/Zn0.95Mg0.05O QCL emitting at 5.27 THz. The theoretical results are compared with those from GaN/Al x Ga1?x N QCLs of similar geometry. Higher calculated optical output powers [ $ {P}_{\rm{ZnMgO}} $ = 2.89 mW (nonpolar) at 5.27 THz and 2.75 mW (polar) at 4.93 THz] are obtained with the ZnO/Zn0.95Mg0.05O structure as compared with GaN/Al0.05Ga0.95N QCLs [ $ {P}_{\rm{AlGaN}} $ = 2.37 mW (nonpolar) at 4.67 THz and 2.29 mW (polar) at 4.52 THz]. Furthermore, a higher wall-plug efficiency (WPE) is obtained for ZnO/ZnMgO QCLs [24.61% (nonpolar) and 23.12% (polar)] when compared with GaN/AlGaN structures [14.11% (nonpolar) and 13.87% (polar)]. These results show that ZnO/ZnMgO material is optimally suited for THz QCLs. 相似文献
20.
The analysis of R0A products as a function of magnetic field in n-on-p diodes using a simple diffusion current model has previously been shown
to yield both Jep/Jtotal ratio (the relative contribution of the p-side diffusion current) and μep (the minority carrier, electron mobility). In this paper, we report the good agreement between the experimental and theoretical
dependence of μep on the hole concentration over a wide range between 1 x 1016 and 4 x 1017 cm−3 in n-on-p homojunction diodes fabricated on undoped p-type Hg0.78Cd0.22Te liquid phase epitaxial (LPE) films. The averaged Jep/Jtotal ratio varied between 68 and 90% with the hole concentration. These Jep/Jtotal ratios indicate that other leakage current mechanisms than the p-side diffusion current were not negligible. Also, for the
first time, comparative measurements were made on p+/n heterojunction diodes consisting of As-doped Hg0.07Cd0.30Te and In-doped Hg0.78Cd0.22Te LPE layers. Unlike a typical change in R0A products by a factor of 2–3 in n-on-p homojunction diodes, the R0A products in p+/n heterojunction diodes at 7 kG were typically only 2–3% higher than that at the zero field. The typical Jep/Jtotal ratio in p+/n heterojunction diodes was about 3–4 %, which confirms the general belief that the p+ cap layer, due to the high doping and a larger bandgap, contributes very little to the total leakage current. 相似文献