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11.
Effect of SiO2 Encapsulation on the Nitrogen Reorganization in a GaNAs/GaAs Single Quantum Well 下载免费PDF全文
Effects of SiO2 encapsulation and rapid thermal annealing on the optical properties of a GaNAs/GaAs single quantum well (SQW) are studied by low-temperature photoluminescence (LTPL). After annealing at 800℃ for 30s, a blueshift of the LTPL peak energy for the SiO2-capped region is 25meV and that for the bare region is 0.8 meV. The results can attribute to the nitrogen reorganization in the GaNAs/GaAs SQW. It is also shown that the nitrogen reorganization can be obviously enhanced by SiO2 cap-layer. A simple model is used to describe the SiO2-enhanced blueshift of the LTPL peak energy. The estimated activation energy of the N atomic reorganization for the samples annealing with and without SiO2 cap-layer are 2.9eV and 3.1 eV, respectively. 相似文献
12.
Molecular Beam Epitaxy Growth and Photoluminescence of Type-Ⅱ (GaAs1-xSbx/InyGa1-yAs)/GaAs Bilayer Quantum Well 下载免费PDF全文
We report a systematical study on the molecular beam epitaxy growth and optical property of (GaAs1-xSbx/InyGa1-yAs)/GaAs bilayer quantum we]] (BQW) structures. It is shown that the growth temperature of the wells and the sequence of layer growth have significant influence on the interface quality and the subsequent photoluminescence (PL) spectra. Under optimized growth conditions, three high-quality (GaAsSb0.29/In0.4 GaAs)/GaAs BQWs are successfully fabricated and a room temperature PL at 1314 nm is observed. The transition mechanism in the BQW is also discussed by photoluminescence and photoreflectance measurements. The results confirm experimentally a type-Ⅱ band alignment of the interface between the GaAsSb and InGaAs layers. 相似文献
13.
High quality above 3-μm mid-infrared InGaAsSb/AlGaInAsSb multiple-quantum well grown by molecular beam epitaxy 下载免费PDF全文
The GaSb-based laser shows its superiority in the 3–4 μm wavelength range. However, for a quantum well(QW) laser structure of InGaAsSb/AlGaInAsSb multiple-quantum well(MQW) grown on GaSb, uniform content and high compressive strain in InGaAsSb/AlGaInAsSb are not easy to control. In this paper, the influences of the growth temperature and compressive strain on the photoluminescence(PL) property of a 3.0-μm InGaAsSb/AlGaInAsSb MQW sample are analyzed to optimize the growth parameters. Comparisons among the PL spectra of the samples indicate that the In0.485GaAs0.184Sb/Al0.3Ga0.45In0.25As0.22Sb0.78MQW with 1.72% compressive strain grown at 460 C posseses the optimum optical property. Moreover, the wavelength range of the MQW structure is extended to 3.83 μm by optimizing the parameters. 相似文献
14.
Very long wavelength infrared focal plane arrays with 50% cutoff wavelength based on type-Ⅱ In As/GaSb superlattice 下载免费PDF全文
A very long wavelength infrared(VLWIR) focal plane array based on In As/Ga Sb type-Ⅱ super-lattices is demonstrated on a Ga Sb substrate. A hetero-structure photodiode was grown with a 50% cut-off wavelength of 15.2 μm, at 77 K.A 320×256 VLWIR focal plane array with this design was fabricated and characterized. The peak quantum efficiency without an antireflective coating was 25.74% at the reverse bias voltage of-20 mV, yielding a peak specific detectivity of 5.89×1010cm·Hz~(1/2)·W~(-1). The operability and the uniformity of response were 89% and 83.17%. The noise-equivalent temperature difference at 65 K exhibited a minimum at 21.4 mK, corresponding to an average value of 56.3 mK. 相似文献
15.
We have studied a two-electron quantum dot molecule in a magnetic field. The electron interaction is treated accurately by the direct diagonalization of the Hamiltonian matrix. We calculate two lowest energy levels of the two-electron quantum dot molecule in a magnetic field. Our results show that the electron interactions are significant, as they can change the total spin of the two-electron ground state of the system by adjusting the magnetic field between S = 0 and S = 1. The energy difference AE between the lowest S = 0 and S = 1 states is shown as a function of the axial magnetic field. We found that the energy difference between the lowest S = 0 and S = 1 states in the strong-B S = 0 state varies linearly. Our results provide a possible realization for a qubit to be fabricated by current growth techniques. 相似文献
16.
Growth and Characterization of GaSb-Based Type-Ⅱ InAs/GaSb Superlattice Photodiodes for Mid-Infrared Detection 下载免费PDF全文
InAs/GaSb superlattiee (SL) midwave infrared photovoltaic detectors are grown by molecular beam epitaxy on GaSb(001) residud p-type substrates. A thick GaSb layer is grown under the optimized growth condition as a buffer layer. The detectors containing a 320-period 8ML/SML InAs/GaS5 SL active layer are fabricated with a series pixel area using anode sulfide passivation. Corresponding to 50% cutoff wavelengths of 5.0 μm at 77K, the peak directivity of the detectors is 1.6 × 10^10 cm.Hz^1/2 W^-1 at 77K. 相似文献
17.
2-μm single longitudinal mode GaSb-based laterally coupled distributed feedback laser with regrowth-free shallow-etched gratings by interference lithography 下载免费PDF全文
We report a type-I Ga Sb-based laterally coupled distributed-feedback(LC-DFB) laser with shallow-etched gratings operating a continuous wave at room temperature without re-growth process. Second-order Bragg gratings are fabricated alongside the ridge waveguide by interference lithography. Index-coupled LC-DFB laser with a cavity of 1500 μm achieves single longitudinal mode continuous-wave operation at 20℃ with side mode suppression ratio(SMSR) as high as 24 dB.The maximum single mode continuous-wave output power is about 10 mW at room temperature(uncoated facet). A low threshold current density of 230 A/cm~2 is achieved with differential quantum efficiency estimated to be 93 mW/A. The laser shows a good wavelength stability against drive current and working temperature. 相似文献
18.
19.
GaSb-based type-I quantum well cascade diode lasers emitting at nearly 2-μm wavelength with digitally grown AlGaAsSb gradient layers 下载免费PDF全文
We report a GaSb-based type-I quantum well cascade diode laser emitting at nearly 2-μm wavelength. The recycling of carriers is realized by the gradient AlGaAsSb barrier and chirped GaSb/AlSb/InAs electron injector. The growth of quaternary digital alloy with a gradually changed composition by short-period superlattices is introduced in detail in this paper. And the quantum well cascade laser with 100-μm-wide, 2-mm-long ridge generates an about continuous-wave output of 0.8 W at room temperature. The characteristic temperature T0 is estimated at above 60 K. 相似文献
20.
采用分子束外延技术对δ掺杂GaAs/AlxGa1-xAs二维电子气(2DEG)样品进行了生长. 在样品生长过程中, 分别改变掺杂浓度(Nd)、空间隔离层厚度(Wd) 和AlxGa1-xAs中Al组分(xAl)的大小, 并在双温(300 K, 78 K)条件下对生长的样品进行了霍尔测量; 结合测试结果, 分别对Nd, Wd及xAl与GaAs/AlxGa1-xAs 2DEG的载流子浓度和迁移率之间的关系规律进行了细致的分析讨论. 生长了包含有低密度InAs量子点层的δ掺杂GaAs/AlxGa1-xAs 2DEG 样品, 采用梯度生长法得到了不同密度的InAs量子点. 霍尔测量结果表明, 随着InAs量子点密度的增加, GaAs/AlxGa1-xAs 2DEG的迁移率大幅度减小, 实验中获得了密度最低为16×108/cm2的InAs量子点样品. 实验结果为内嵌InAs量子点的δ掺杂GaAs/AlxGa1-xAs 2DEG的研究和应用提供了依据和参考.
关键词:
二维电子气
InAs量子点
载流子浓度
迁移率 相似文献