Investigations on the interface abruptness in CBE-grown InGaAs/InP QW structures

In this work we present a detailed analysis of chemical beam epitaxy-grown (CBE) InGaAs/InP multi quantum well (MQW) interfaces to explain experimental data from high quality single and multi-QWs. Our results compare well with the best published data we have obtained some outstanding results. For example, the very intense absorption peak and the high number of satellite peaks in the diffraction rocking curve, were obtained even on samples grown in non-optimized conditions. A careful use of growth interruption at the interfaces allows us to obtain monolayer (ml) interfaces. Nevertheless, the switching of the group V element at each interface leads to strain formation. This effect could become dramatic in superlattice structures with periods smaller than about 5 nm and barriers of less than 3–4 nm. More generally, the conditions for the growth of high quality single and multiple QWs is discussed in this work and these will be correlated with fourier transform photoluminesence (FTPL), high resolution x-ray diffraction (HRXRD), absorption, photo-absorption and photo-current (in PIN structures) measurements.     

选择区域生长高质量InGaAsP多量子阱材料

采用LP-MOVPE在SiO2掩膜的InP衬底上实现了高质量的InGaAsP多量子阱(MQW)的选择区域生长(SAG).通过改变生长温度和生长压力,MQW的适用范围由C波段扩展至L波段,即MQW的光致发光波长从1546nm延展至1621nm.光致发光（PL）测试表明：在宽达75nm的波长范围内,MQW的质量与非选择生长的MQW质量相当,并成功制作出电吸收调制DFB激光器（EML）.     

Optimal growth interrupts for very high quality InGaAs(P)/InP superlattices grown by MOVPE

The effects of different growth interrupt schemes at the compositional interfaces in 30 period InGaAs(P)/InP superlattices grown by metal-organic vapor phase epitaxy have been studied for quarternary compositions λ = 1.35 and 1.52 μm as well as for the ternary case λ = 1.67 μm. The best full width at half maximum of the photoluminescence peaks at 4 K are 7–8 meV for the InGaAsP/InP and 4.6 meV for the InGaAs/InP superlattices indicating extremely high optical quality and vertical homogenity of the samples. However, strong memory effects relating to both the presence and the absence of arsenic are evident from x-ray diffraction measurements. Reactor purging as a remedy is limited by the surface roughening and defect formation induced by a non-equilibrium vapor phase composition. Optimal growth interrupts must therefore be determined considering both the interface smoothness and abruptness and will in general be composition dependent.     

选择区域生长高质量InGaAsP多量子阱材料

采用 L P- MOVPE在 Si O2 掩膜的 In P衬底上实现了高质量的 In Ga As P多量子阱 (MQW)的选择区域生长(SAG) .通过改变生长温度和生长压力 ,MQW的适用范围由 C波段扩展至 L 波段 ,即 MQW的光致发光波长从15 46 nm延展至 16 2 1nm.光致发光 (PL)测试表明 :在宽达 75 nm的波长范围内 ,MQW的质量与非选择生长的MQW质量相当 ,并成功制作出电吸收调制 DFB激光器 (EML) .     

InxGa1−xAs/InP quantum well structures grown on [111]B InP

We report growth and characterization details of lattice matched and coherently strained In_xGa_1−xAs/InP quantum well structures grown on misoriented [111]B InP substrates. Photoluminescence from a range of such structures, grown on substrates with optimum misorientation, show linewidths as good or better than equivalent [100] layers. Multiquantum well (MQW) samples with relatively modest compressive strain show X-ray diffraction data characteristic of highly uniform pseudomorphic quantum wells. With increased strain (x = 0.63), relaxation is evident through a degradation of the diffracted peak widths and through the observation of defects in the surface morphology. Fabricated strained p-i(MQW)-n diode structures exhibit low reverse leakage current densities (e.g. j = 6 μA/cm²). Room temperature photocurrent measurements on these devices show a strong excitonic blue shift (15 nm) with applied bias, as a consequence of the built-in piezoelectric field. The rate of peak shift, up to 8 nm/V, demonstrates excellent potential for low voltage optical modulator applications at around 1.55 μm wavelength.     

Detuning adjustable multiwavelength MQW-DFB laser array grown byeffective index/quantum energy control selective area MOVPE

A multiwavelength MQW DFB laser array with novel structure Is described. Oscillation wavelength and gain peak wavelength were simultaneously controlled on the same epitaxial wafer by using modulated grown thicknesses of selectively grown InGaAs/InGaAsP/InP MQW active waveguides. The laser array with constant-pitch built-in corrugation fabricated by a simple DFB laser process demonstrated 10.1 nm controllable range for lasing wavelength and 45 nm for gain peak wavelengths, with uniform lasing properties and narrow spectral linewidths. The technique is attractive for light sources used in WDM/FDM applications     

全固源分子束外延InAsP/InGaAsP多量子阱1.55μm激光器

利用新型全固源分子束外延技术 ,对 1 .5 5 μm波段的 In As P/ In Ga As P应变多量子阱结构的生长进行了研究。实验表明 ,较低的生长温度或较大的 / 束流比有利于提高应变多量子阱材料的结构质量 ,而生长温度对材料的光学特性有较大的影响。在此基础上生长了分别限制多量子阱激光器结构 ,制作的氧化物条形宽接触激光器实现了室温脉冲工作 ,激射波长为 1 5 63 nm,阈值电流密度为 1 .4k A/ cm2 。这是国际上首次基于全固源分子束外延的 1 .5 5 μm波段 In As P/ In Ga As P多量子阱激光器的报道     

带有阶梯缓变集电区的InP/InGaAs/InP DHBT材料研究

设计并生长了一种新的InP/InGaAs/InP DHBT结构材料,采用在基区和集电区之间插入两层不同禁带宽度的InGaAsP四元系材料的阶梯缓变集电结结构,以解决InP/InGaAs/InP DHBT集电结导带尖峰的电子阻挡效应问题。采用气态源分子束外延(GSMBE)技术,通过优化生长条件,获得了高质量的InP、InGaAs以及与InP晶格相匹配的不同禁带宽度的InGaAsP外延材料。在此基础上,成功地生长出带有阶梯缓变集电区结构的InP基DHBT结构材料。     

InGaAs（P）／InP应变量子阱和超晶格的光电性质

利用低压金属有机化合物化学汽相沉积（ＭＯＣＶＤ）生长技术在ＩｎＰ衬底上生长ＩｎＧａＡｓ／ＩｎＰ应变量子阱，超晶格和ＩｎＧａＡｓＰ／ＩｎＰ量子阱结构材料，利用７７Ｋ光荧光（ＰＬ）测量这一应变量了阱和量子阱的光学性质，利用双晶Ｘ光测量应变超晶格的性质。     

Measurement of group effective index in integrated semiconductoroptical waveguides

The effective group index of InGaAsP/InP moderately diluted multiple quantum well (MQW) waveguides grown by metalorganic chemical vapor deposition (MOCVD/sur) on InP has been measured in the 1.55-μm spectral region. The technique used is based on the Fourier analysis of the spectral transmission function of a resonant cavity formed by the waveguide itself. Accuracy to the third decimal place is demonstrated, and differences between TE and TM indexes are also evidenced     

Structural and optical properties of AlxGa1-xN/AlyGa1-yN multiple quantum wells for deep ultraviolet emission

The AlxGa1-xN/AlyGa1-yN multiple quantum well (MQW) structure for deep ultraviolet emission has been grown on sapphire by metal organic chemical vapor deposition (MOCVD).High resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), and cath-odoluminescence (CL) are used to characterize the structural and optical properties of MQWs, respectively.Clear step flows can be observed in the AFM image indicating a two-dimensional growth model.There are many cracks on the surface of the MQW structure because of the high tensile stress.HRXRD shows multiple satellite peaks to the 2rid order.The HRXRD simulation shows that the MQW period is about 11.5 nm.The emission peak of AlxGa1-xN/AlyGa1-yN MQWs is about 295 nm in the deep ultraviolet region from the CL spectra.     

InGaAs／InP分别限制量子阱激光器的阱数优化设计和实验制备

根据对ＩｎＧａＡｓＰ－ＩｎＰ分别限制量子阱激光器结构的注入效率的分析和利用Ｘ射线衍射结ＩｎＧａＡｓＰ－ＩｎＰ２０个周期的多量子阱结构异质界面的研究，设计，制备了４个阱的ＩｎＧａＡｓＰ－ＩｎＰ分别限制量子阱激光器结构，利用质子轰击制得条形激光器，阈值电流为１００ｍＡ，直流室温连续工作，单面输出外微分子效率为３６％。     

InGaAs/InGaAlAs MQW lasers with InGaAsP guiding layers grown by gas source molecular beam epitaxy

An InGaAs/InGaAlAs multiple-quantum-well (MQW) laser was grown by gas source molecular beam epitaxy (GS-MBE). The laser has InP cladding layers and InGaAsP guiding layers, and the active layer is composed of an InGaAs/InGaAlAs MQW layer. Electrons are injected into the MQW active layer by tunneling through the barriers. The threshold current of the InGaAs/InAlAs buried-heterostructure (BH)-MQW lasers was as low as 9.6 mA. The relaxation oscillation frequency of the InGaAs/InAlAs MQW lasers was found to be larger than that of the InGaAs/InGaAsP MQW lasers with the same structure.<>     

Interface strain in organometallic vapor phase epitaxy grown InGaAs/InP superlattices

The spatial distribution of strain in organometallic vapor phase epitaxy grown InGaAs/InP superlattice structures has been studied by varying the thicknesses of the InGaAs well and the InP barrier layers and measuring the strain. High resolution x-ray diffraction rocking curves were used to measure the strain from angular separation between the zeroth-order superlattice peak and the substrate (004) peak. The results are consistent with a compressive strain resulting from arsenic carryover into the InP following InGaAs growth. The strain is not localized at the interfaces but extends into the InP barrier layer. The amount of arsenic carryover increases with the growth time of the InGaAs well.     

MOCVD growth of strained multiple quantum well structure for 1.3 μm InAsP/InP laser diodes

In this article, we describe the growth and characterization for 1.3 μm InAsP/InP strained multiple quantum well (SMQW) laser diodes (LDs) with separate confinement heterostructure grown at 580°C by metalorganic chemical vapor deposition. The grown strained single quantum well (SSQW) stack and strained multiple quantum well (SMQW) structures are characterized using double-crystal X-ray diffraction and photoluminescence (PL) to confirm the structural and optical qualities for practical device applications. The InAsP/InP SSQW stack grown at 580°C appears to be extremely abrupt, uniform, free of misfit dislocations and narrow PL half width. Although the InAsP/InP SMQWs grown at 580°C maintain its structural integrity throughout the deposition sequence, the slightly broader PL half width for InAsP/InP SMQW structure is attributed to the dislocations resulted from a large net strain. Laser emission can be achieved by using the InAsP/InP SMQWs and the lasing wavelength is in a good agreement with our designed structure. The experimental data of broad-area and ridge waveguide LDs are described in detail.     

Optical and structural properties of MOVPE grown GaxIn1−xAs/InP strained multiple quantum well atructures

This paper presents a study of the structural and optical properties of strained GaInAs/ InP multiple quantum well (MQW) structures fabricated by LP-MOVPE. The composition of the Ga _x In_1−x As films ranged fromx = 0.17 tox = 1.0 and was determined by sputtered neutral mass spectrometry (SNMS) on thick layers. The structures of the MQW samples with well widths from 1.5 to 5 nm were investigated by high resolution x-ray diffraction (HR-XRD). Simulations of the diffraction patterns showed that transition layers of approximately 2 monolayer (ML) thickness with high lattice mismatch exist at the interfaces. Photoluminescence (PL) measurements indicate well widths of a multiple of a monolayer with local variations of one monolayer. The PL peak energies vary smoothly with the Ga concentration. These results were confirmed by optical absorption measurements.     

Lpe highly perfect ingaasp/lnp structure characterization by x-ray double crystal diffractometry

X-ray double crystal diffractometry has been used to assess the crystal quality of InGaAsP/ InP single heterostructures grown by liquid phase epitaxy. Diffraction profiles have been obtained in the parallel non-dispersive configuration, using Cu Kα₁ radiation, 004 symmetric reflection and a perfect InP crystal as a monochromator. Several structures, with different lattice mismatches, ranging from positive to negative values, have been investigated. The epilayer Bragg peak was found to be as narrow as theoretically predicted, if thickness effects are taken into account. Pendellosung fringes have been observed at the low angle side of the peak, thus the epilayer thickness could be measured. Finally, the sample curvature has been evaluated from the broadening of the substrate Bragg peak and, when the broadening was sufficiently large, a good agreement with that calculated from the elastic theory has been found. All the results demonstrate that the structures investigated are characterized by a very high crystal quality.     

InAsP/InGaAsP/InP应变材料的二维倒空间衍射研究

采用X射线衍射三轴二维倒空间衍射图研究了InP(100)衬底上分子束外延生长的压应变InAsP材料和张应变InGaAsP材料. 实验测定了两种材料的（004）面、(224）面的倒空间衍射图，得到了处于部分弛豫状态的InGaAsP在不同方向呈现不同的应变状态. 排除了外延层倾斜及应变对确定失配度的影响，准确计算得到InAsP外延层体失配度为1.446%, InGaAsP外延层体失配度为-0.5849%，并且生长了高质量的应变补偿8阱多量子阱.     

红橙光InGaN/GaN量子阱的结构与光学性质研究

采用金属有机物化学气相沉积(MOCVD)技术生长了具有高In组分InGaN阱层的InGaN/GaN多量子阱(MQW)结构,高分辨X射线衍射(HRXRD)ω-2θ扫描拟合得到阱层In含量28%。比较大的表面粗糙度表明有很大的位错密度。室温下光致荧光(PL)研究发现该量子阱发射可见的红橙光,峰位波长在610 nm附近。变温PL(15～300 K)进一步揭示量子阱在低温下有两个发光机制,对应的发射峰波长分别为538 nm和610 nm。由于In分凝和载流子的局域化导致的载流子动力改变,使得量子阱PL发光峰值随温度增加呈明显的"S"变化趋势。     

抗中子辐射加固超辐射发光二极管的研究

我们设计并制作了一种高性能的抗中子辐射的超辐射发光二极管。高能中子辐射后产生的位移损伤造成器件有源区内少子寿命减少,从而导致器件光输出功率的降低。通过理论分析可知高输出功率的超辐射发光二极管对中子辐射的敏感度较低。本文中的超辐射发光二极管的有源区采用了具有高量子效率和小体积有源区的InGaAsP/InP多量子阱结构,外延波导层采用了线性缓变折射率分别限制结构(GRIN-SCH),并设计和优化出了特殊波导吸收区和腔面减反射膜结构。辐射实验结果显示,在中子注量为6?10₁₃～1?10₁₄n/cm₂(1MeV)下,InGaAsP/InP多量子阱结构的超辐射发光二极管与双异质结结构相比具有更好的抗中子辐射性能。