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Materials Science and Engineering

Virginia Commonwealth University

Electrical and Computer Engineering Publications

2014

Articles 1 - 2 of 2

Full-Text Articles in Electronic Devices and Semiconductor Manufacturing

Spectroscopy Studies Of Straincompensated Mid-Infrared Qcl Active Regions On Misoriented Substrates, Gregory Edward Triplett, Justin Grayer, Charles Meyer, Emily Cheng, Denzil Roberts Jan 2014

Spectroscopy Studies Of Straincompensated Mid-Infrared Qcl Active Regions On Misoriented Substrates, Gregory Edward Triplett, Justin Grayer, Charles Meyer, Emily Cheng, Denzil Roberts

Electrical and Computer Engineering Publications

In this work, we perform spectroscopic studies of AlGaAs/InGaAs quantum cascade laser structures that demonstrate frequency mixing using strain-compensated active regions. Using a three-quantum well design based on diagonal transitions, we incorporate strain in the active region using single and double well configurations on various surface planes (100) and (111). We observe the influence of piezoelectric properties in molecular beam epitaxy grown structures, where the addition of indium in the GaAs matrix increases the band bending in between injector regions and demonstrates a strong dependence on process conditions that include sample preparation, deposition rates, mole fraction, and enhanced surface diffusion …


Orientation-Dependent Pseudomorphic Growth Of Inas For Use In Lattice-Mismatched Mid-Infrared Photonic Structures, Gregory Edward Triplett, Charles Meyer, Emily Cheng Jan 2014

Orientation-Dependent Pseudomorphic Growth Of Inas For Use In Lattice-Mismatched Mid-Infrared Photonic Structures, Gregory Edward Triplett, Charles Meyer, Emily Cheng

Electrical and Computer Engineering Publications

In this study, InAs was deposited on GaAs (100) and GaAs (111)B 2 degrees towardssubstrates for the purpose of differentiating the InAs growth mode stemming from strain and then analyzed using in-situ reflection high energy electron diffraction, scanning electron microscopy, Raman spectroscopy, reflectance spectroscopy, and atomic force microscopy. The procession of InAs deposition throughout a range of deposition conditions results in assorted forms of strain relief revealing that, despite lattice mismatch for InAs on GaAs (approximately 7%), InAs does not necessarily result in typical quantum dot/wire formation on (111) surfaces, but instead proceeds two-dimensionally due primarily to the surface orientation.