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排序方式: 共有262条查询结果,搜索用时 15 毫秒
111.
112.
113.
Farahiyah Mustafa Norfarariyanti Parimon Abdul Manaf Hashim Shaharin Fadzli Abd Rahman Abdul Rahim Abdul Rahman Mohd Nizam Osman 《Superlattices and Microstructures》2010
A Schottky diode was designed and fabricated on an n-AlGaAs/GaAs high electron mobility transistor (HEMT) structure for RF power detection. The processing steps used in the fabrication were the conventional steps used in standard GaAs processing. Current–voltage measurements showed that the devices had rectifying properties with a barrier height of 0.5289–0.5468 eV. The fabricated Schottky diodes detected RF signals well and their cut-off frequencies up to 20 GHz were estimated in direct injection experiments. To achieve a high cut-off frequency, a smaller Schottky contact area is required. The feasibility of direct integration with the planar dipole antenna via a coplanar waveguide transmission line without insertion of matching circuits was discussed. A higher cut-off frequency can also be achieved by reducing the length of the coplanar waveguide transmission line. These preliminary results represent a breakthrough as regards direct on-chip integration technology, towards the realization of a ubiquitous network society. 相似文献
114.
A. Rastelli R. Songmuang O. G. Schmidt 《Physica E: Low-dimensional Systems and Nanostructures》2004,23(3-4):384
We report on a new method to produce self-assembled, unstrained, GaAs/AlGaAs quantum dots (QDs) with large confinement energy. First we create nanoholes on a GaAs surface by growing InAs islands on GaAs(0 0 1), overgrowing them with GaAs and etching the surface in situ with AsBr3 gas. Then we transfer the holes to an AlGaAs surface, fill them with GaAs and overgrow them with AlGaAs. In this way we obtain GaAs inclusions in an AlGaAs matrix. We investigate the optical properties of such QDs by photoluminescence spectroscopy and their morphology by atomic force microscopy. We show that the QD size can be tuned and emission with inhomogeneous broadening down to 8.9 meV can be achieved. 相似文献
115.
Improved thermal property of strained InGaAlAs/AlGaAs quantum wells for 808-nm vertical cavity surface emitting lasers 下载免费PDF全文
Zhuang-Zhuang Zhao 《中国物理 B》2022,31(3):34208-034208
The 808-nm vertical cavity surface emitting laser (VCSEL) with strained In0.13Ga0.75Al0.12As/Al0.3Ga0.7As quantum wells is designed and fabricated. Compared with the VCSELs with Al0.05Ga0.95As/Al0.3Ga0.7As quantum wells, the VCSEL with strained In0.13Ga0.75Al0.12As/Al0.3Ga0.7As quantum wells is demonstrated to possess higher power conversion efficiency (PCE) and better temperature stability. The maximum PCE of 43.8% for 10-μm VCSEL is achieved at an ambient temperature of 30 ℃. The size-dependent thermal characteristics are also analyzed by characterizing the spectral power and output power. It demonstrates that small oxide-aperture VCSELs are advantageous for temperature-stable performance. 相似文献
116.
L. Buydens P. Demeester M. Van Ackere A. Ackaert P. Van Daele 《Journal of Electronic Materials》1990,19(4):317-321
Experiments have been carried out to investigate thickness variations between epitaxial layers grown on ridges or channels
and the surrounding planar surface. Results show a remarkable variation in growth velocity, even for relatively wide channels
and ridges. Using these findings, a novel laser/waveguide coupling technique, which uses a single epitaxial growth step, is
proposed. 相似文献
117.
Baumann J. A. Michel C. Marek H. Serreze H. B. Schachter R. 《Journal of Electronic Materials》1990,19(4):363-366
The performance characteristics of epitaxial structures suitable for optoelectronic and electronic devices were investigated.
These were fabricated by MOVPE using tertiary-butylarsine, a non-hydride arsenic source. Minority carrier diffusion lengths
of 5μm at 3 × 1018/cm3 and 2μm at 2 × 1019/cm3 were achieved inp-type GaAs. Recombination velocities at the GaAs/AlGaAs interface are reduced to 1 × 103 cm/sec by processing under appropriate conditions. Electron mobilities of 4000 cm2/V-sec inn-type (2 × 1017/cm3) layers resulted in transconductances of 120 mS/mm in 1.5μm gate depletion mode MESFETs. The above values are comparable to those obtained with arsine in this work and others reported
in the literature. 相似文献
118.
Highly purified trimethylaluminum [(CH3)3Al] was prepared by reducing the contamination of volatile impurities such as organic silicon and dimethyl-aluminum methoxide [(CH3)2AlOCH3]. The concentration of methoxy group in (CH3)3Al was found to decrease considerably when (CH3)2Al was distilled in the presence of aluminum trihalide. Among the halides, purification efficiency increased in the order I>Br>Cl. High-quality AlGaAs layer and AlGaAs/GaAs modulation doped structures were grown by organometallic vapor-phase epiloxy (OMVPE) using the purified (CH3)3Al. Their electrical properties were discussed in relation to the volatile impurity in the source gas. 相似文献
119.
借助一新的工艺模拟与异质器件模型用CAD软件──POSES(Poisson-SchroedingerEquationSolver),对以AlGaAs/InGaAs异质结为基础的多种功率PHEMT异质层结构系统(传统、单层与双层平面掺杂)进行了模拟与比较,确定出优化的双平面掺杂AlGaAs/InGaAs功率PHEMT异质结构参数,并结合器件几何结构参数的设定进行器件直流与微波特性的计算,用于指导材料生长与器件制造。采用常规的HEMT工艺进行AlGaAs/InGaAs功率PHEMT的实验研制。对栅长0.8μm、总栅宽1.6mm单胞器件的初步测试结果为:IDss250~450mA/mm;gm0250~320mS/mm;Vp-2.0-2.5V;BVDS5~12V。7GHz下可获得最大1.62W(功率密度1.0W/mm)的功率输出;最大功率附加效率(PAE)达47%。 相似文献
120.
用光荧光(PL)和时间分辨光谱(TRPL)技术研究了GaAS/AIGaAS量子阱结构中荧光上升时间τf和激子谱线半宽(FWHM)随阱宽的变化关系,发现在窄阱中,τf,随阱宽的变化关系与宽阱时的情况恰恰相反,在窄阱中τf随着阱宽的减小而增加,归结为激子二维特性的退化导致声学声子对激子的散射作用减弱造成的.同时观测到窄阱中谱线半宽随着阱宽减小而增加,这也是因为激子特性由维二维向三维转化造成的. 相似文献