Journal ArticleDOI
Excitonic enhancement of optical gain in quantum wells
TLDR
In this article, the authors studied the optical gain in terms of the transition between a localized state and a continuous subband state with small carrier concentration, and showed that the enhanced optical gain is strongly enhanced by excitonic effects through the coupling between the two transitions.Abstract:
Excitonic effects of optical gain in quantum wells have been studied theoretically in a three-band model. Taking into account an additional localized level in the energy gap, we obtain the optical gain in terms of the transition between a localized state and a continuous subband state with small carrier concentration. Simultaneously, excitonic absorption also occurs near the band-edge transition. It is shown that the optical gain is strongly enhanced by excitonic effects through the coupling between the two transitions. This enhanced optical gain might show the realization of very-low-threshold current-laser diodes.read more
Citations
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Journal ArticleDOI
Diameter-dependent electromechanical properties of GaN nanowires.
TL;DR: The diameter-dependent Young's modulus, E, and quality factor, Q, of GaN nanowires were measured using electromechanical resonance analysis in a transmission electron microscope and imply significant advantages of smooth-surfaced GaNnanowire resonators for nanoelectromechanical system (NEMS) applications.
Journal ArticleDOI
Observation of confinement-dependent exciton binding energy of GaN quantum dots
TL;DR: The photoluminescence emission peak energy of GaN quantum dots was observed to shift to higher energy with decreasing quantum dot size as discussed by the authors, which was found to be a combination of a blueshift from the confinement-induced shift of the electronic levels and a redshift from the increased Coulomb energy induced by a compression of the exciton Bohr radius.
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Intense photoluminescence from self-assembling InGaN quantum dots artificially fabricated on AlGaN surfaces
TL;DR: In this article, photoluminescence from self-assembling InGaN quantum dots (QDs), which are artificially fabricated on AlGaN surfaces via metalorganic chemical vapor deposition, is demonstrated.
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Disorder effects in focused-ion-beam-deposited Pt contacts on GaN nanowires.
TL;DR: The current-bias characteristics at various temperatures, T, of focused-ion-beam (FIB)-deposited Pt contacts on GaN nanowires evolves from low-resistance ohmic (linear I-V) to rectifying as the diameter increases, and both exhibit strongly nonmetallic T-dependence.
Journal ArticleDOI
Defects in GaN Nanowires
TL;DR: In this article, high-resolution transmission electron microscopy (HRTEM) and X-computed tomography (XTEM) were used to characterize common defects in wurtzite GaN nanowires grown via a vapor-liquid-solid (VLS) mechanism.