多变量离子注入型量子阱混杂效应

为实现InP基单片集成光电子器件和系统,对InGaAsP/InGaAsP分别限制异质结多量子阱激光器结构展开量子阱混杂(QWI)技术研究。在不同能量P离子注入、不同快速热退火(RTA)条件以及循环退火下,研究了有源区量子阱混杂技术,实验结果采用光致发光(PL)谱进行表征。实验结果表明:在不同变量下皆可获得量子阱混杂效果,其中退火温度影响最为显著,且循环退火可进一步提高量子阱混杂效果;PL谱蓝移随着退火温度、退火时间和注入能量的增大而增大,退火温度对蓝移的影响最大,在注入剂量为1×10^14 ion/cm2,注入能量为600keV,750℃二次退火150s时获得最大蓝移量116nm。研究结果为未来基于QWI技术设计和制备单片集成光电子器件和系统奠定了基础。     

快速热退火对InGaAsSb/AlGaAsSb多量子阱材料发光特性的影响

I型InGaAsSb/AlGaAsSb量子阱是1.8～3μm波段锑化物半导体激光器的首选材料,为进一步提升分子束外延生长的InGaAsSb/AlGaAsSb量子阱材料的光学性能,本文对其进行了快速热退火处理,通过光致发光光谱研究了快速热退火对量子阱材料光致发光特性的影响。光致发光光谱测试结果表明,快速热退火会使量子阱结构中垒层、阱层异质界面处的原子互扩散,改善量子阱材料的晶体质量,促使结构释放应力,进而提高了量子阱材料的光学性能。随着退火温度升高,量子阱材料的室温光致发光谱峰位逐渐蓝移,在500,550,600℃退火后,量子阱材料光致发光谱的峰位分别蓝移了7,8,9 meV。通过变温及变功率光致发光光谱测试,确认了样品发光峰的来源,位于0.687 eV的发光峰为局域载流子的复合,位于0.701 eV的发光峰为自由激子的复合。对不同退火温度的样品进一步研究后发现,退火温度的升高降低了材料中局域态载流子复合的比例,在600℃退火温度下局域载流子与自由激子的强度比值降为500℃退火温度下的22.6%,这表明合适温度的快速热退火处理可以有效改善量子阱材料的光致发光特性。     

离子注入法Mn掺杂InAs/GaAs量子点的光磁性质

用离子注入法对InAs/GaAs量子点掺杂Mn离子,量子点样品经过快速退火处理后同时具有低温铁磁性和发光性能.注Mn量子点发光峰在退火后蓝移,在较高注入剂量的样品中这种由于互扩散带来的蓝移受到抑制,认为这与样品中的缺陷以及Mn聚集在量子点周围减小量子点所受的应力,同时形成的团簇阻碍了界面上原子的互扩散作用有关.Mn在盖层中形成了GaMnAs和小的Mn颗粒,表现出较好的低温铁磁性.     

离子注入法Mn掺杂InAs/GaAs量子点的光磁性质

用离子注入法对InAs/GaAs量子点掺杂Mn离子,量子点样品经过快速退火处理后同时具有低温铁磁性和发光性能.注Mn量子点发光峰在退火后蓝移,在较高注入剂量的样品中这种由于互扩散带来的蓝移受到抑制,认为这与样品中的缺陷以及Mn聚集在量子点周围减小量子点所受的应力,同时形成的团簇阻碍了界面上原子的互扩散作用有关.Mn在盖层中形成了GaMnAs和小的Mn颗粒,表现出较好的低温铁磁性.     

二氧化硅覆盖退火增强磷化铟基体激光器材料的量子阱混合

我们对SiO2覆盖退火增强InGaAs/InGaAsP/InP激光器材料量子阱混合技术进行了实验研究.相对于原始样品,退火时无SiO2覆盖的样品经800℃,30s快速退火后,其光致发光谱的峰值波长“蓝移”了7nm,退火时有SiO2覆盖的样品经过同样的快速退火后,其光致发光谱的峰值波长“蓝移”了56nm.即在同一片子上实现了在需要量子阱混合的区域带隙的“蓝移”足够大的同时,不希望量子阱混合的区域能带结构的变化创记录的小.本文认为增大量子阱的宽度、采用无应力的量子阱结构以及引入足够厚的缓冲层可以改善量子阱材料的晶格质量,有利于提高量子阱混合技术的可靠性与重复性,     

注碳外延硅的荧光特性研究

研究了注碳外延硅经氢气退火及电化学腐蚀处理后的荧光特性。经能量为50keV,剂量为2×1016cm-2的碳离子注入后的外延单晶硅片,在氢气氛下高温退火及电化学腐蚀处理。荧光谱仪分析表明电化学腐蚀是蓝光发射的前提,并且不同的电化学腐蚀条件对发光强度和峰位影响极大。不同的激发光波长亦可影响发光谱的峰位。     

磷离子注入诱导InGaAsP／InP双量子阱混合的研究

本文用光荧光(PL)方法研究了磷离子注入具有两个不同发射波长的InGaAsP/InP双量子阱结构引起的混合。注入能量为120keV,剂量范围为1×1011-1×1014/cm2。注入后,在高纯氮保护下,样品在700℃进行快速热退火30秒。实验结果表明,小剂量注入(～1011/cm2)能较好地诱导近表面阱的混合,且两个阱保持了不同发射波长,说明离子注入诱导量子阱混合与注入深度有关。大剂量注入(>1012/cm2)时,发射波长为1.59μm量子阱混合的程度(蓝移值大于130nm)超过了1.52μm量子阱混合的程度,且两个阱的PL发射峰基本上合并成一个单峰。     

MOCVD生长1.06μm波段InGaAs/GaAs单量子阱材料的发光特性研究

利用金属有机化学气相沉积(MOCVD)技术,在不同偏向角的GaAs衬底上生长了InGaAs/GaAs单量子阱外延结构。通过对样品室温光致发光(PL)谱测试结果的分析,讨论了衬底偏向角、量子阱层生长温度以及V/III比对外延片发光波长、发光强度及PL谱半峰全宽(FWHM)的影响。发现在相同生长条件下,对于InGaAs/GaAs应变量子阱结构,在GaAs(100)偏111A晶向较小偏向角的衬底上生长的样品PL谱发光强度较大,半峰全宽较窄;量子阱层低温生长的样品发光强度更强;增大量子阱层V/III比可以提高样品的发光强度,同时PL谱峰值波长出现红移。     

基于循环退火技术的InGaAs/AlGaAs量子阱混杂

为了解决由于激光器腔面处的光吸收引起的腔面光学灾变损伤(COD),采用无杂质空位扩散(IFVD)法,研究了由SiO2电介质层诱导的InGaAs/AlGaAs量子阱结构的带隙蓝移。使用等离子化学气相沉积(PECVD)在InGaAs/AlGaAs量子阱的表面生长SiO2电介质层;然后采用IFVD在N2环境下进行高温退火实验,从而实现量子阱混杂(QWI)。实验结果表明:蓝移量的大小随退火时间和电介质层厚度的变化而变化,样品覆盖的电介质层越厚,在相同的退火温度下承受的退火时间越长,得到的蓝移量也越大。然而,在高温退火中的时间相对较长时,退火对量子阱造成的损坏相当大。高温短时循环退火,能够在保护量子阱晶体质量的同时实现QWI。通过在850℃退火6min下循环退火5次,得到了46nm的PL蓝移,且PL峰值保持在原样品的80%以上。     

离子注入法制备GaAsl量子阱集成多波长发光芯片

报道了用离子注入方法和组合技术制备的ＡｌＧａＡｓ／ＧａＡｓ单量子阱多波长发光集成芯片,利用量子阱果面混合原理在同一块ＧａＡｓ衬底片上获得了２０多个发光波长从７８７￣７２４ｎｍ的ＧａＡｓ量子阱发光单元,研究了不同剂量的Ａｓ和Ｈ离子分别单独注入和迭加组合注入对量子阱发光峰位的影响,采用了组事技术和离子注入技术大大筒化了制备工艺过程,这种上发光芯片对于波分复用器件和建立离子注入数据库等方面都有重要的意义     

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.     

Effects of rapid thermal annealing on InAsP/InP strainedmultiquantum well laser diodes grown by metal organic chemical vapourdeposition

The authors report on the effect of rapid thermal annealing (RTA) on the performance of InAsP/InP strained multiquantum well (SMQW) laser diodes (LDs) grown by metal organic chemical vapour deposition. From the photoluminescence (PL) measurements, the optimal RTA temperature for the InAsP/InP strained single quantum well (SSQW) stack was found to be 700°C. The 700°C annealed SSQW stack was found to have a stronger PL peak intensity, no halfwidth broadening and small peak shift, indicating that the degree of interdiffusion of group-V elements can be much reduced. The threshold current and slope efficiency of the 700°C RTA SMQW LDs can be reduced significantly as compared to those of as-grown LDs     

InGaAsP/InP Double Quantum Well Intermixing Induced by Phosphorus Ion Implantation

A quantum well intermixing(QWI) investigation on double quantum well(DQW) structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing (RTA) was carried out by means of photoluminescence(PL). The ion implantation was performed at the energy of 120 kev with the dose ranging from 1 × 1011 cm-2 to 1× 1014 cm-2. The RTA was performed at the temperature of 700 ℃ for 30 s under pure nitrogen protection. The PL measurement implied that the band gap blue-shift from the upper well increases with the ion dose faster than that from lower well and the PL peaks from both QWs remained well separated under the lower dose implantation(～1×1011 cm-2 ) indicating that the implant vacancy distribution affects the QWI. When the ion dose is over ～ 1 × 1012 cm-2 , the band gap blue-shift from both wells increases with the ion dose and finally the two peaks merge together as one peak indicating the ion implantation caused a total intermixing of both quantum wells.     

Optical properties of InAs<Subscript>1−x</Subscript>N<Subscript>x</Subscript>/In<Subscript>0.53</Subscript>Ga<Subscript>0.47</Subscript>As single quantum wells grown by gas source molecular beam epitaxy

Optical properties of InAs_1−xN_x/In_0.53Ga_0.47As (hereafter, abbreviated as InAsN/InGaAs) single quantum wells (SQWs) grown on InP substrates by gas source molecular-beam epitaxy are studied using photoluminescence (PL) measurements. By comparing the low-temperature PL spectra of InAs/InGaAs and InAsN/InGaAs SQWs, InAs and InAsN phases are found to coexist in the InAsN layer. Such serious alloy inhomogeneities result in obvious exciton localization by potential irregularities. The blue shift of the PL peak after rapid thermal annealing (RTA) is found to originate mainly from As-N interdiffusion inside the well layer. According to the temperature-dependent PL results, uniformity of the InAsN layer can be effectively improved by RTA, and the exciton localization is, thus, relieved. Comparison of luminescence quenching and excitation-power-dependent PL behavior between the QWs with and without nitrogen content suggests that the quality of the QW is degraded by the introduction of nitrogen, and the degradation can only be partially recovered by post-growth RTA.     

Effect of postgrowth heat treatment on the structural and optical properties of InP/InAsP/InP nanowires

The effect of the postgrowth annealing of InP/InAsP/InP heterostructural nanowires produced by molecular-beam epitaxy on their structural and optical properties is studied. It is shown that the procedure of short-term (1 min) annealing in an argon atmosphere provides a means for increasing the emission intensity of InAsP quantum dots, suppressing the emission from InAsP quantum wells formed as a result of lateral growth, and substantially reducing the density of structural defects in the nanowires.     

采用As2和As4模式的新型全固源InAsP分子束外延生长

在国产分子束外延设备的基础上,利用新型阀控裂解As源炉,对As2和As4的生长特性进行了全面的研究.以As2和As4两种模式,在(001)InP衬底上生长了高质量的InAsP体材料和InAsyP1-y/InP多量子阱样品.材料质量用X射线衍射(XRD)以及室温和低温的光致发光(PL)测定.实验发现,两种模式生长的样品的晶体结构质量相当,但As2的吸附系数明显大于As4的吸附系数.另外,用As2模式生长的多量子阱样品的室温光学特性优于As4模式生长的样品,但在低温时,二者几乎相同,这是由As4较为复杂的生长机制所引入的缺陷造成的.     

Processing parameters for selective intermixing of GaAs/AIGaAs quantum wells

Some of the parameters which determine the amount of intermixing of GaAs/AIGaAs quantum wells (QWs) using SiO₂ capping and rapid thermal annealing (RTA) have been studied using photoluminescence (PL) techniques. The degree of intermixing of QWs was found to be larger for thicker SiO₂ capping layers and for shorter distances between the QWs and the oxide-wafer interface. A maximum PL energy difference of 90 meV was observed between the region covered by a 1.3 μm thick oxide layer and the non-oxide region in a wafer that was annealed at 1100° C for 15 s.     

Super-flat interfaces in In0.53Ga0.47As/In0.52Al0.48As quantum wells grown on (411)A InP substrates by molecular beam epitaxy

Effectively atomically flat interfaces over a macroscopic area (“(411)A super-flat interfaces”) were successfully achieved in In_0.53Ga_0.47As/In_0.52Al_0.48As quantum wells (QWs) grown on (411)A InP substrates by molecular beam epitaxy (MBE) at a substrate temperature of 570°C and V/III=6. Surface morphology of the In_0.53Ga_0.47As/In_0.52Al_0.48As QWs was smooth and featureless, while a rough surface of those simultaneously grown on a (100) InP substrate was observed. Photoluminescence (PL) linewidths at 4.2 K from the (411)A QWs with well width of 0.6–12 nm were 20–30 % narrower than those grown on a (100) InP substrate and also they are almost as narrow as each of split PL peaks for those of growth-interrupted QWs on a (100) InP substrate. In the case of the (411)A QWs, only one PL peak with very narrow linewidth was observed from each QW over a large distance (7 mm) on a wafer.     

Implant Compositional Disordering on InGaAs／InP MQW Structures

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Si3N4无杂质空位诱导InGaAs/InP 量子阱结构带隙的蓝移

用光荧光谱和二次离子质谱的方法,研究了由Si3N4电介质薄膜引起的无杂质空位诱导InGaAs/InP多量子阱结构的带隙蓝移。实验中选用Si3N4作为电介质层,用以产生空位,并经快速热退火处理。实验结果表明,带隙蓝移同退火时间和退火温度有关,合理选用退火条件可以控制带隙的蓝移量。二次离子质谱分析表明,电介质盖层Si3N4和快速热退火导致量子阱中阱和垒之间互扩,这种互扩是导致带隙蓝移的主要原因。