Low-strain, quantum-cascade-laser active regions grown on metamorphic buffer layers for emission in the 3.0-4.0 μm wavelength region
Low-strain, quantum-cascade-laser active regions grown on metamorphic buffer layers for emission in the 3.0-4.0 μm wavelength region
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在变质缓冲层上生长的低应变量子级联激光有源区，可在 3.0-4.0 μm 波长范围内发射
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
C. Gmachl
中科院分区：
文献类型：
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作者：
L. Mawst;J. Kirch;Taewan Kim;T. Garrod;C. Boyle;D. Botez;B. Zutter;K. Schulte;T. Kuech;P. Bouzi;C. Gmachl
我们已经研究了变质缓冲层（MBL），作为所谓的虚拟衬底，用于访问In的组成范围
X
ga
1-X
砷/铝
y
在
1-y
作为超晶格（SL）材料，否则当在常规衬底上生长时由于过度应变而被禁止。这样的材料在实现短发射波长（即，≤ 4.0 μ m）。模拟研究表明，显着增强性能方面的降低器件的温度灵敏度和降低热阻是可能的，在传统的InP衬底器件采用基于MBL的QCL设计在GaAs衬底上。此外，与在3.0 - 4.0 μ m波长范围内发射的InP上的传统QCL相比，这种器件将表现出显著更低的应变。为了提高MBL顶面的平面度，我们采用化学机械抛光（CMP）之前的QCL SL结构的生长。20-期间
X
ga
1-X
As（威尔斯）/Al
y
在
1-y
作为（障碍）SL生长的InGaAs阶梯梯度，氢化物气相外延（HVPE）生长MBL的金属有机气相外延（MOVPE）。在SL生长之前，在MBL的顶部上采用CMP，导致显著改善的X射线衍射SL条纹。采用单级QCL-SL有源区材料在经过CMP的MBL上生长的电致发光器件在3.6 μ m附近显示出子带间发射。
We have investigated metamorphic buffer layers (MBLs), as so-called virtual substrates, for accessing a compositional range of In
x
Ga
1-x
As/Al
y
In
1-y
As superlattice (SL) materials which would otherwise be prohibited due to excessive strain when grown on conventional substrates. Such materials have application in the realisation of high-performance Quantum Cascade Lasers (QCLs) of short emission wavelengths (i.e., ≤4.0 μm). Simulation studies suggest that significant enhancement of performance in terms of reduced device temperature sensitivity and reduced thermal resistance is possible over conventional InP-substrate devices by employing MBL-based QCL designs on a GaAs substrate. Furthermore, such devices would exhibit significantly lower strain compared to conventional QCLs on InP emitting within the 3.0-4.0 μm wavelength region. To improve the planarity of MBL top surfaces, we employ chemical mechanical polishing (CMP) prior to the growth of the QCL SL structures. 20-period In
x
Ga
1-x
As (wells)/Al
y
In
1-y
As (barriers) SLs are grown by metalorganic vapour phase epitaxy (MOVPE) on an InGaAs step-graded, hydride vapour phase epitaxy (HVPE)-grown MBL. Employing CMP on the top of the MBL, prior to the SL growth, results in significantly improved X-ray-diffraction SL fringes. Electroluminescent devices, incorporating a single stage of QCL-SL active-region material grown on an MBL subjected to CMP, demonstrate intersubband emission near 3.6 μm.