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用光调制反射谱(PR)测量了三块应变层 In_xGa_(1-x)As/GaAs 量子阱多重结构样品,每块样品中包含宽度为140、80、50、30和20A的量子阱.在300K和77K的PR谱中观察到各个量子阱的11H和11L光跃迁.根据PR数据用包络函数法进行分析,估算了量子阱中In的成分.在解释300K和77K实验结果时考虑了流体静压形变势常数的温度依赖性.实验和理论最佳符合时求得导带边不连续性在300K为0.7,77K为0.66. 相似文献
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报道了GaAs-AIAs多量子阱(MQW)结构的室温光调制反射(PR)光谱。与2K下光荧光激发谱的对比表明室温下激子作用的重要性。讨论了GaAs-AlAsMQW结构的PR调制机制,指出它仍可能是表面电场调制,但不同于体材料的情形,而是具有一阶微商本质,并且在弱场条件下以量子化子带及相应激子带隙的斯塔克移动的调制为主。 相似文献
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提出一种微接触电调制反射谱(LCER)测试方法,该方示与无接触电调制反射(CER)谱相比较,可极大降低调制电压。给出了自制的详细样品架结构,测量了InGaAs/GaAs量子阱样品,并与光调制反射谱(PR)相比较,结果证实了此方法的可行性和高光谱灵敏度,表明样品与电极的轻微接触既对测量结果没有明显的影响,又可简化测试条件,降低对测量环境的要求,是研究半导体材料和微结构一种方便而又有效的方法。 相似文献
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报道了MBE生长的CdTe/Cd1-xMnxTe:In调制掺杂应变层多量子附材料的光荧光光谱,低温下观察到一个由多电子-单个空穴散射引起的很强的费密边奇异的发光现象,对应于费密边能量位置发光峰有一个很强的增加,使整个发光锋具有明显的非对称性.分析讨论了引起费密边奇异现象的物理机制,测量了77K下CdTe/Cd1-xMnxTe:In样品的调制光谱,与荧光光谱进行了比较,结果进一步支持了本文的结论.还测量了费密迪奇异随温度的变化,结果表明此现象在Ⅱ—Ⅵ族半导体多量子附材料中比Ⅲ─V族材料强得多. 相似文献
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对In(0.2)Ga(0.8)As/GaAs应变多量子阱在77K下的光调制反射谱(PR)和热调制反射谱(TR)进行了实验研究.对PR结果的线形拟合指认了应变多量子阱中子能级的跃迁,并与理论计算结果作了比较.实验对比确认PR中11H、13H等跃迁结构为非耦合态、具有电场调制机构的一阶微商性质.而11L、31H、22H等跃迁结构为阶间耦合态,对这些隧穿耦合的低场调制产生三阶微商特性. 相似文献
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Suitable growth conditions for strained AlGaInAs grown on GaAs substrates by molecular beam epitaxy (MBE) are presented, and strained layer multiple quantum well AlGaInAs lasers grown by MBE are demonstrated. Low-temperature photoluminescence was used to characterize quantum wells grown at different temperatures with different Al, Ga, and In compositions to establish growth parameters 相似文献
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《Solid-state electronics》1986,29(2):215-227
Recent developments in the studies of GaAs/GaAlAs multi-quantum-well (MQW) structures using high-resolution photoluminescence spectroscopy are reviewed. Results discussed in this paper are all obtained in quantum wells grown using molecular-beam epitaxy (MBE). The observed linewidths of the excitonic transitions are very small (in many cases < 0.2 meV), thus indicating a high quality of the quantum wells. Theories of crystal growth by MBE using Monte Carlo techniques and of excitonic lineshape in quantum wells are reviewed. Based on the observed linewidths of the excitonic transitions, a microscopic model for the GaAs/GaAlAs interface is proposed. Variations of the energies of the various transitions in MQW structures as a function of the well size are presented and are compared with the available calculations. The behavior of the excitonic transitions as a function of temperature and applied electric field is also reviewed. 相似文献
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2μm InGaSb/AlGaAsSb strained quantum wells and a tellurium-doped GaSb buffer layer were grown by molecular beam epitaxy(MBE).The growth parameters of strained quantum wells were optimized by AFM, XRD and PL at 77 K.The optimal growth temperature of quantum wells is 440℃.The PL peak wavelength of quantum wells at 300 K is 1.98μm,and the FWHM is 115 nm.Tellurium-doped GaSb buffer layers were optimized by Hall measurement.The optimal doping concentration is 1.127×1018 cm-3 and the resistivity is 5.295×10-3Ω·cm. 相似文献
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用分子束外延系统生长了GaAs/AlGaAs非对称耦合双量子阱(ACDQW),用组合注入的方法,在同一块衬底上获得了不同注入离子和不同注入剂量的耦合量子阱单元,没有经过快速热退火过程,在常温下测量了不同单元的显微光荧光谱,发现了带间跃迁能量最大变化范围接近100meV,组合注入所导致的能量移动要大于单独注入导致的能量移动。 相似文献
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N. A. Maleev A. Yu. Egorov A. E. Zhukov A. R. Kovsh A. P. Vasil’ev V. M. Ustinov N. N. Ledentsov Zh. I. Alferov 《Semiconductors》2001,35(7):847-853
Two designs of vertical-cavity surface-emitting lasers (VCSELs) for the 1.3 μm spectral range on GaAs substrates with active
regions based on InAs/InGaAs quantum dots and InGaAsN quantum wells are considered. The relationship between the active region
properties and optical microcavity parameters required for lasing has been investigated. A comparative analysis is made of
VCSELs with active regions based on InAs/InGaAs quantum dots or on InGaAsN quantum wells, which are fabricated by MBE and
demonstrate room-temperature CW operation. Optimization of the vertical microcavity design provides single-pass internal optical
losses lower than 0.05%.
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Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 35, No. 7, 2001, pp. 881–888.
Original Russian Text Copyright ? 2001 by Maleev, Egorov, Zhukov, Kovsh, Vasil’ev, Ustinov, Ledentsov, Alferov. 相似文献
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研究了GaInNAs/GaAs多量子阱在不同温度和激发功率下的光致发光(PL)谱以及光调制反射(PR)谱.发现PL谱主发光峰的能量位置随温度的变化不满足Varshni关系,而是呈现出反常的S型温度依赖关系.进一步测量,特别是在较低的激发光功率密度下,发现有两个不同来源的发光峰,它们分别对应于氮引起的杂质束缚态和带间的激子复合发光.随温度变化,这两个发光峰相对强度发生变化,造成主峰(最强的峰)的位置发生切换,从而导致表观上的S型温度依赖关系.采用一个基于载流子热激发和出空过程的模型来解释氮杂质团簇引起的束缚态发光峰的温度依赖关系. 相似文献