共查询到20条相似文献,搜索用时 77 毫秒
1.
研究了分子束外延技术生长的PbSe/PbSrSe多量子阱结构的中红外光致荧光现象.高分辨率X射线衍射(HRXRD)谱观察到了多量子阱所特有的多级卫星峰,表明量子阱界面陡峭.变温光致荧光谱测量显示量子阱结构对电子空穴有强的限制效应,在相同温度下,量子阱样品的荧光峰峰位相对PbSe体材料有一定的蓝移.发现量子阱样品的荧光强度同温度有关,温度从150 K上升到230 K时,荧光强度逐渐增大,温度继续升高,荧光强度缓慢下降,但在高于室温时,仍能观察到较强的荧光发射,这说明该量子阱结构材料具有应用于室温工作的中红外
关键词:
PbSe/PbSrSe多层量子阱(MQWs)
光致中红外荧光
高分辨X射线衍射(HRXRD) 相似文献
2.
3.
采用反应射频磁控溅射方法,在Si(001)基片上制备了具有高c轴择优取向的ZnO/MgO多量子阱.利用X射线反射、X射线衍射、电子探针,光致荧光光谱等表征技术,研究了ZnO/MgO多量子阱的结构、成份和光致荧光特性.研究结果表明,多量子阱的调制周期在1.85—22.3 nm之间,所制备的多量子阱具有量子限域效应,导致了室温光致荧光峰的蓝移,并观测到了量子隧穿效应引起的荧光效率下降.建立了基于多声子辅助激子复合跃迁理论的室温光致荧光光谱优化拟合方法,通过室温光致荧光光谱拟合发现,ZnO/MgO比ZnO/ZnMgO多量子阱具有更大的峰位蓝移,探讨了导致光致荧光光谱展宽的可能因素.
关键词:
ZnO/MgO
多量子阱
磁控溅射
光致荧光
量子限域效应 相似文献
4.
5.
以CdSe纳米晶体为核,用胶体化学的方法,通过化学替代反应,获得了不同阱层或不同垒层的CdSeHgSeCdSe量子点量子阱(QDQW)晶体.紫外可见光吸收谱研究表明,通过调节QDQW中间HgSe阱层的厚度从0.9nm至0,可以调节QDQW颗粒的带隙从1.8变化至2.1eV,实现QDQW纳米晶体的剪裁.光致荧光(PL)谱研究显示,QDQW形成后,CdSeHgSe纳米颗粒表面态得到钝化,显现出发光强度加强的带边荧光峰.利用有效质量近似模型,对QDQW晶粒内部电子的1s—1s态进行了估算,估算结果总体趋势与实验数据相符
关键词:
量子点量子阱晶体 能带剪裁 加强的带边荧光峰 相似文献
6.
采用感应耦合等离子体刻蚀技术对InAsP/InP应变多量子阱和InAsP/InGaAsP应变单量子阱材料的覆盖层进行了不同厚度的干法刻蚀. 实验结果表明,干法刻蚀后量子阱光致荧光强度得到了不同程度的增强. 干法刻蚀过程不仅增加了材料表面粗糙度,同时使其内部微结构发生变化. 采用湿法腐蚀方法去除表面变粗糙对量子阱发光特性的影响,得到干法刻蚀覆盖层20 nm后应变单量子阱微结构变化和其表面粗糙度变化两个因素分别使荧光强度提高1.8倍和1.2倍的结果.
关键词:
干法刻蚀
应变多量子阱
光致发光谱
损伤 相似文献
7.
分别用光致发光谱(PL),光伏谱(PV)及时间分辨谱(TRPL)的方法,测量了应变InGaAs/GaAs单量子阱和多量子阱在不同温度下的光谱,发现单量子阱与多量子阱有不同的光学4性质。多量子阱PL谱发光峰和PV谱激子峰的强度与半高宽都比单量子阱的大,但单量子阱的半高宽随着温度的升高增大很快,这是由激子-声子耦合引起的,通过时间分辨谱研究发现了量子阱子能级之间的跃迁,多量子阱的发光寿命明显比单量子阱的长,我们利用形变势模型对量子阱的能带进行了计算,很好地解释了实验结果。 相似文献
8.
9.
10.
11.
《Superlattices and Microstructures》1994,15(3):313
An optical spectroscopic study of wide band gap AlGaInP based quantum wells is reported. GaInP quantum wells with AIGaInP barriers of two different Al compositions are studied. Type-II behaviour for narrow quantum wells with AlInP barriers is demonstrated. The onset of this behaviour allows limits to be placed on the size of the valence band offset. The first three orders of LO-phonon satellites are observed in quantum well PL spectra and their relative intensities are compared with theoretical predictions. 相似文献
12.
D. K. Loginov E. V. Ubyĭvovk Yu. P. Efimov V. V. Petrov S. A. Eliseev Yu. K. Dolgikh I. V. Ignat’ev V. P. Kochereshko A. V. Sel’kin 《Physics of the Solid State》2006,48(11):2100-2108
The optical reflection spectra of semiconductor GaAs/AlGaAs structures with wide quantum wells are studied experimentally. A theoretical analysis of the spectra is performed in terms of the exciton-polariton model in the approximation of quantum confinement of the exciton center of mass with regard to the contributions of both heavy and light excitons to the crystal polarization. The applicability range of the theory of the center-of-mass confinement for GaAs/AlGaAs heterostructures is estimated. It is established that, for quantum wells more than 180 nm wide, the interference effects observed in the reflection spectra of polariton waves are reproduced, to a good accuracy, by theoretical calculations based on the quantum confinement of the exciton center of mass. For quantum-well widths less than 150 nm, the experimental results are described better by the model of quantum confinement of electrons and holes. 相似文献
13.
Shulin Gu Ronghua Wang Ping Han Liqun Hu Rong Zhang Youdou Zheng 《Superlattices and Microstructures》1992,12(4)
Infrared absorption has been used to investigate the subband structures in SiGe/Si quantum wells. The quantum wells are prepared using RRH/VLP-CVD and consist of 20 periods of
and 60 periods of
. The good periodical and interface sharpness of the SiGe/Si quantum wells have been shown by Auger Electron Spectroscopy (AES). The absorption peaks due to transitions between the hole subbands and the conduction band have been observed in infrared absorption spectra. The transverse photocurrent spectrum parallel to the growth plane have also shown absorption peaks due to transitions between the heavy and light hole band states and the conduction band states in quantum wells. 相似文献
14.
N.E. Kaputkina Yu.E. Lozovik 《Physica E: Low-dimensional Systems and Nanostructures》2005,26(1-4):291
Direct and indirect excitons in coupled quantum wells and in coupled quantum dots are studied. We consider excitons with two-dimensional, quasi-two-dimensional and three-dimensional carriers. Problems were investigated for a wide range of characteristic parameters—confining to potential steepness, distances between quantum wells or dots, effective width of wells and magnetic fields. The mutual influence of the controlling parameters of the problem on exciton properties is analyzed. Energy and wave function spectra were calculated and dispersion law and effective masses were obtained. 相似文献
15.
L. E. Vorob’ev V. Yu. Panevin N. K. Fedosov D. A. Firsov V. A. Shalygin S. Hanna A. Seilmeier Kh. Moumanis F. Julien A. E. Zhukov V. M. Ustinov 《Physics of the Solid State》2004,46(1):118-121
High-resolution spectroscopy in the mid-infrared spectral range is used to study electronic transitions between size-quantization subbands in stepped quantum wells under picosecond interband excitation. The contributions from intersubband and intrasubband absorption of light are separated by using the difference in time profiles of the absorption coefficient for these cases. For stepped quantum wells, spontaneous interband luminescence and superluminescence are studied for different excitation levels. For structures with quantum dots, the intraband absorption spectra for n-and p-type structures and the spectra of photoinduced intraband absorption and emission (for polarized radiation) for undoped structures are studied. 相似文献
16.
V. F. Agekyan A. Yu. Serov A. Yu. Stepanov N. G. Filosofov G. Karczewski 《Physics of the Solid State》2010,52(10):2181-2185
The optical spectra of the CdTe/Cd0.7Mn0.3Te structure containing three CdTe quantum wells with nominal thicknesses of 16, 8, and 4 monolayers have been investigated.
The temperature dependences of parameters of the exciton luminescence spectra (integrated intensity, full-width at half-maximum,
position of the maximum, Stokes shift) for quantum wells with different thicknesses differ substantially. These differences
are explained by a strong thickness dependence of the energy of Coulomb coupling in the exciton, the energy of localization
of the exciton on bulges of the quantum well, and the degree of penetration of the exciton wave function into the barrier.
At high excitation power densities, the emission contours of the quantum wells with thicknesses of 8 and 16 monolayers contain
short-wavelength tails that correspond to optical transitions between excited quantum-well levels. 相似文献
17.
Properties of Strain Compensated Symmetrical Triangular Quantum Wells Composed of InGaAs/InAs Chirped Superlattice Grown Using Gas Source Molecular Beam Epitaxy
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We investigate the properties of symmetrical triangular quantum wells composed of InGaAs/InAs chirped superlattice, which is grown by gas source molecular beam epitaxy via digital alloy method. In the quantum well structure tensile AlInGaAs are used as barriers to partially compensate for the significant compressive strain in the wells, the strain compensation effects are confirmed by x-ray measurement. The photoluminescence spectra of the sample are dominated by the excitonic recombination peak in the whole temperature range. The thermal quenching, peak energy shift and line-width broadening of the PL spectra are analysed in detail, the mechanisms are discussed. 相似文献
18.
A. Klochikhin A. Reznitskii L. Tenishev S. Permogorov S. Ivanov S. Sorokin Kh. Mumanis R. Seisyan C. Klingshirn 《JETP Letters》2000,71(6):242-245
Absorption and luminescence of the quantum wells formed by the (Zn-Cd)Se and (Ga-In)As solid solutions are studied in the range of exciton size-quantization ground state. The spectra observed are described by a model assuming the two-dimensional character of fluctuation states in quantum wells and the presence of a percolation threshold within the absorption contour. 相似文献
19.
The spectra of reflection and absorption of monochromatic light by semiconductor quantum wells whose width is comparable to the wavelength of exciting radiation are calculated. The case of resonance with two closely spaced excited levels is considered. These levels can arise as a result of splitting of the electron-hole pair energy due to the magnetopolaron effect when the quantum well is placed in a strong magnetic field directed perpendicular to the plane of the quantum well. It is demonstrated that, in wide quantum wells, unlike in narrow quantum wells, the reflectance and absorptance of light depend on the quantum-well width. The theory is applicable at any reciprocal ratio of the radiative lifetime to the nonradiative lifetime of electronic excitations. 相似文献
20.
In this article, we presented a study of InAs0.04P0.96/InP Bragg-spaced quantum wells (BSQWs), which were grown by metal organic chemical vapor deposition (MOCVD). The quantum wells were characterized by photoluminescence (PL), double-crystal x-ray diffraction (DC-XRD), and reflection spectra. We found that the BSQWs structure grown at 580 °C appears to be extremely abrupt, uniform, free of misfit dislocations, and of narrow PL line width. From the reflection spectra at different temperatures, we presented a theoretical analysis of the changes in band structure for resonant and near-resonant wells, and proposed a new scheme of using the temperature to tune the Bragg resonance of Bragg spaced quantum wells. 相似文献