共查询到18条相似文献,搜索用时 46 毫秒
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应变层多量子阱InGaAs—GaAs的光电流谱研究 总被引:2,自引:0,他引:2
在10—300K温度范围,用光电流谱方法研究了未掺杂的x为0.1、0.15和0.2,InGaAs层厚度为8和15nm的In_xGa_(1-x)As—GaAs应变层多量子阱的能带结构。在1.240—1.550eV光子能量范围,除11H、11L和22H激子跃迁以及GaAs的基本带间跃迁外,还观察到束缚子带到连续带的跃迁。对样品In_(0.15)Ga_(0.85)As(8nm)-GaAs(15nm),观察到11H重空穴激子的2s及其它激发态跃迁,由此得到激子结合能的近似值,约为8meV。重空穴能带台阶Q_v=0.40±0.02。应变效应使得电子和重空穴束缚在InGaAs层,而轻空穴束缚在GaAs层。 相似文献
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测量了GaAs/AlGaAs多量子阱红外探测器在零偏压、小偏流和大偏压等条件下的光电流谱,并结合理论计算的光跃迁能量讨论了光电流谱的多峰结构和异常增强特性。 相似文献
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We used the time-resolved equipment consisting of a streak camera and normal photoluminescence set-up to measure the transcient behavior of the PL from the InGaAs/GaAs single quantum well sample, and thus obtained both the temporal resolution and the spectral resolution of the photoluminescence. A rapid decay of PL signal from the GaAs layer and the slow PL decay from the InGaAs well have beed found. From the experimetal results, the trapping efficiency of the carriers by the well is estimated to be about 80%. 相似文献
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<正> 当由两种晶格失配的材料组成量子阱时,只要每层的厚度小于临界值,则两种材料会通过应变而使界面处不产生失配位错,可获高质量的晶体材料。这谓之应变层超晶格结构。本 相似文献
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We present systematic studies of the alloy disorder dependence of line-widths in InGaAs/GaAs strained-layer quantum wells grown by molecular beam epitaxy using both photoluminescence and optical absorption. Indium composition of the samples under investigation ranged from 0.1 to 0.2. The effects of well-size variation were measured and analyzed, In all cases we were able to observe the exciton transition and the increase of linewidths with a content and well size. In addition, variations of the lineshape were found with the increasing temperature in optical absorption. The experimental data by the virtual crystal approximation and are analysed.The results obtained from this study show the alloy disorder is the dominant mechanism for line broadening at a low temperature, which is in contrast with the case of GaAs/AlGaAs structure, where the principal broadening mechanism is the interface roughness at the low temperature. This information is important for optimizing the crystal-growth condition and improving the quality of crystal-grown structures. 相似文献
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The photocurrent (PC) spectroscopy of the GaAs/AlAs and GaAs/ AlGaAs superlattices (SLs) are studied by using a P-i-N photodiode structure in which the intrinsic regions are composed of SLs. The measurements were made at different temperatures ranging from 15K to 300K and with the application of transverse dc electric field. A sequence of exciton absorption peaks were observed and assigned according to the theoretical predictions based on the Kronig-Penney model calculations of sublevel energies in the coupled multiple quantum wells (MQWs). The SL structure parameters were checked by both the absolute peak positions and the heavy and light hole splittings. The quantum confined Stark effect of excitonic transitions in MQWs which is closely dependent on the barrier and well layer thicknesses was studied. The assignment of some forbidden transitions was proved by different ways. The PC spectroscopy was also measured by the excitation of linear polarized light in a side illumination mode.The anisotropic effect showed distinct features related to heavy and light holes, respectively. 相似文献
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The ultrafast photoexcited carrier dynamics in bulk GaAs and GaAs/ AlGaAs multiple quantum well(MQW)structure has been studied using femtosecond laser pulse pump-probe techniques on the samples grown by MBE. A hot carrier cooling time of 1.5ps in MQW is measured at room temperature. Also, optical phonon emission at 33meV is observed in this sample. These results are found to be similar to that observed in bulk GaAs. A comparison of the hot carrier cooling rates for the two cases suggests that the infra-sub-band optical phonon scattering in MQW may play a dominant role in the cooling of highly excited hot carriers for the narrow wells. The experimental results agree well with that predicted by a simple infinite depth square-well model. 相似文献
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用低压MOCVD(LP-MOCVD)生长三种不同的InGaAs/GaAs应变层量子阱材料,其中两种含AlGaAs限制层。结果表明,AlGaAs限制层对量子阱的发光强度影响很大,与没有AlGaAs限制层的结果相比,带AlGaAs限制层的结构的发光强度要强一个数量级以上。在低温(18K)PL光谱图中,我们看到,除了存在主峰以外,在主峰两侧还各有一个子峰,这些子峰可能与量子阱的质量有关。 相似文献
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报道调制掺杂AlGaAs/InGaAs/GaAs应变量子阱结构的分子束外延生长、变温霍尔效应和电化学c—v测量,并对输运性质进行了讨论。用这种材料研制的PM-HEMT(pseudomorphic high electron mobility transistors)器件,栅长0.4μm,在12GHz下噪声系数1.03dB,相关增益7.5dB。 相似文献
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本文研究了F~+离子注入诱导InGaAsP/InGaAs多量子阱结构,并着重研究了晶格匹配和失配应力对F~+离子注入诱导无序的影响,用变温光荧光(13~300K)方法研究了和带隙直接有关的光荧光峰值随温度变化的规律。在13K条件下,F~-离子注入具有压应力应变层的样品导致光荧光峰产生35meV的蓝移,而对具有张应力的样品,仅产生8meV的蓝移。定性地分析了产生不同程度蓝移的原因。 相似文献
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Dorokhin M. V. Demina P. B. Danilov Yu. A. Vikhrova O. V. Kuznetsov Yu. M. Ved’ M. V. Iikawa F. Balanta M. A. G. 《Semiconductors》2020,54(10):1341-1346
Semiconductors - The results of studies of the time-resolved photoluminescence in semiconductor heterostructures containing two noninteracting InGaAs quantum wells in a GaAs matrix are reported.... 相似文献
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StrainedInGaAs/GaAsquantumwel(QW)laserswithemisionwavelengthof980nmarecurentlyreceivingconsiderableatentionbecau... 相似文献