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Effects of hydrostatic pressure and external electric field on the impurity binding energy in strained GaN/Al_xGa_(1-x)N spherical quantum dots

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Optoelectronics Letters 2012年第3期8卷 224-228页

作者：达来木仁闫祖威石磊 School of Physics Science and Technology Inner Mongolia University College of Science Inner Mongolia Agricultural University

The binding energy and Stark effect energy shifts of a shallow donor impurity state in a strained GaN/AlxGa1-xN spherical finite-potential quantum dot (QD) are calculated using a variational method based on the effective mass approximation. The binding energy is computed as a function of dot size and hydrostatic pressure. The numerical results show that the binding energy of the impurity state increases, attains a maximum value, and then decreases as the QD radius increases for any electric field. Moreover, the binding energy increases with the pressure for any size of dot. The Stark shift of the impurity energy for large dot size is much larger than that for the small dot size, and it is enhanced by the increase of electric field. We compare the binding energy of impurity state with and without strain effects, and the results show that the strain effects enhance the impurity binding energy considerably, especially for the small QD size. We also take the dielectric mismatch into account in our work.

关键词： Binding energy Electric fields Gallium Hydrostatic pressure semiconductor quantum dots

Room temperature continuous wave operation of 1.33-um InAs/GaAs quantum dot laser with high output power

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Chinese Optics Letters 2006年第7期4卷 413-415页

作者：韩勤牛智川倪海桥张石勇杨晓红杜云佟存柱赵欢徐应强彭红玲吴荣汉 State Key Laboratory on Integrated Optoelectronics National Laboratory for Superlattices and Microstructures Institute of SemiconductorChinese Academy of Sciences

Continuous wave operation of a semiconductor laser diode based on five stacks of InAs quantum dots （QDs） embedded within strained InGaAs quantum wells as an active region is demonstrated. At room temperature, 355-mW output power at ground state of 1.33-1.35 μm for a 20-μm ridge-waveguide laser without facet coating is achieved. By optimizing the molecular beam epitaxy （MBE） growth conditions, the QD density per layer is raised to 4 × 10^10 cm^-2. The laser keeps lasing at ground state until the temperature reaches 65 ℃.

关键词： Continuous wave lasers Epitaxial growth Molecular beam epitaxy Semiconducting indium gallium arsenide semiconductor quantum dots semiconductor quantum wells

Low-temperature characteristics of two-color InAs/InP quantum dots laser

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Chinese Optics Letters 2012年第4期10卷 40-43页

作者：李世国龚谦王新中岳丽柳庆博王海龙 Department of Electronic Communication and Technology Shenzhen Institute of Information Technology State Key Laborator of Functional Materials for Informatics Shanghai Institute of Microsystem and Informantion TechnologyChinese Academy of Sciences Shangdong Provincial Key Laboratory of Laser Polarization and Information Technology Department of PhysicsQufu Normal University

We report on the lasing characteristics of a two-color InAs/InP quantum dots（QDs）laser at a low *** lasing peaks with a tunable gap are simultaneously *** a low temperature of 80 K,a tunable range greater than a 20-nm wavelength is demonstrated by varying the injection current from 30 to 500 *** a special condition,we even observe three lasing peaks,which are in contrast to those observed at room *** temperature coefficient of the lasing wavelength was obtained for the two colors in the 80-280 K temperature range,which is lower than that of the reference quantum well（QW）laser working in the same wavelength region.

关键词： Color semiconductor quantum dots Temperature

Influence of excitation power on temperature-dependent photoluminescence of phase-separated InGaN quantum wells

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Chinese Optics Letters 2016年第4期14卷 73-77页

作者：吕海燕吕元杰王强李建飞冯志红徐现刚冀子武 School of Physics Shandong University Jinan 250100 China National Key Laboratory of Application Specific Integrated Circuit (ASIC) Hebei Semiconductor Research Institute Shijiazhuang 050051 China Key Laboratory of Functional Crystal Materials and Device (Ministry of Education) Shandong University Jinan 250100 China

Temperature-dependent photoluminescence （PL） of phase-separated InGaN quantum wells is investigated over a broader excitation power range. With increasing excitation power from 0.5 pW to 50 mW, the In-rich quasi-quantum dot （QD）-related PL peak disappears at about 3 mW, while temperature behavior of the InGaN matrix-related PL peak energy （linewidth） gradually evolves from a strong ＂S-shaped＂（＂W-shaped＂） temperature dependence into a weak ＂S-shaped＂（an approximately ＂V-shaped＂）, until becoming an inverted ＂V-shaped＂（a monotonically increasing） temperature dependence. This indicates that, with increasing excitation power, the carrier localization effect is gradually reduced and the QD-related transition is submerged by the significantly enhanced InGaN matrix-related transition, while the carrier thermalization effect gradually increases to become predominant at high excitation powers.

关键词： Photoluminescence quantum efficiency quantum optics semiconductor quantum dots Temperature distribution

Colloidal Alloy Magic-Size Clusters: Room-Temperature Synthetic Approach and Formation Pathway

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Colloidal Alloy Magic-Size Clusters: Room-Temperature Synthe...