Engineering topics
Publications and source records attributed to Leon, R..
The time of carrier transfer into a dot decreases with increasing dot density as well as with photoexcited carrier denstiy and temperature. It is suggested that potential barriers at the barrier, wetting layer and quantum dot interfaces hinder the carrier capture in low-density quantum dot structures.
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High humidity and temperature test (known as 85/85 tests) were performed on various III-V devices and structures to determine environmental effects in non-hermetically packaged GaAs membrane mixer diodes.
Transmission electron microscopy is used to study the morphology and the composition profile of pure Ge islands grown at high temperature on (001) Si by molecular beam epitaxy.
We report significant differences in the temperature dependent and time-resolved photoluminescence(PL) from low and high surface density InGaAs/GaAs quantum dots (QDs).
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A transition between two types of step alignment was observed in a multilayered InGaAs/GaAs quantum-dot (QD) structure. A change to larger QD sizes in smaller concentrations occurred after formation of a dislocation array.
InGaAs/GaAs island formation during vapor phase epitaxy showed diverging behaviors when varying group V partial pressures (PP). Differences include changes in critical thicknesses for the onset of the Stranski-Krastanow (S-K) transformation, surface coverages, ratios between coherent and incoherent islands, and dissimilar morphologies upon annealing.
Large variations in InGaAs quantum dot concentrations were obtained with simultaneous growths on vicinal GaAs[001] substrates with different surface step densities.
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Interfacial compositional disordering in InGaAs/GaAs quantom dots has been used to tune their intersublevel energy spaceings (delta E subscript [(i + 1) - i]).
We have successfully fabricated intersubband GaAs/AlGaAs quantum well infrared photodetectors grown on GaAs-on-Si substrate and evaluated their structural, electrical, and optical characteristics. We have found that the performance is comparable to a similar detector structure grown on a semi-insulating GaAs substrate.
Diverging behaviors are observed in the InGaAs/GaAs Stranski-Krastanow (S-K) island formation during vapor phase epitaxy: varying group V partial pressures gives different critical thicknesses for the onset of the S-K transformation, island surface coverages, ratios between coherent and incoherent islands, and dissimilar morphologies upon annealing.