The a-SiNx:H with a large bandgap of 3.8 eV was utilized to decorate ZnO nanowires. The UV emission from the a-SiNx:H-decorated ZnO nanowires are greatly enhanced compared with the undecorated ZnO nanowire. The deep-level defect emission has been completely suppressed even though the sample was annealed at temperatures up to 400 °C. The incorporation of H and N is suggested to passivate the def...

InAs/GaAsBi dot-in-well structures were fabricated using gas-source molecular beam epitaxy and investigated for its optical and structural properties. GaAsBi-strained buffer layer and strain reduction layer are both effective to extend the photoluminescence (PL) emission wavelength of InAs quantum dot (QD). In addition, a remarkable PL intensity enhancement is also obtained compared with low-te...

Correlation in crystallite sizes and defects of epitaxial ZnO layers deposited on 6H-SiC substrates has been addressed. The biaxial strain governs the ZnO crystallites for the layer thickness of 400 nm. The misfit dislocations were observed in nucleation and theater is the columnar growth mode diffracted in transmission electron microscopy. The columnar growth mode is a symbol of stacking fault...

The photoluminescence behavior of CdS quantum dots in initial growth stage was studied in connection with an annealing process. Compared to the as-synthesized CdS quantum dots (quantum efficiency ≅ 1%), the heat-treated sample showed enhanced luminescence properties (quantum efficiency ≅ 29%) with a narrow band-edge emission. The simple annealing process diminished the accumulated defect states...

Temperature invariant output slope efficiency and threshold current sT0=`d in the temperature range of 5–75 °C have been measured for 1.3 μm p-doped self-organized quantum dot lasers. Similar undoped quantum dot lasers exhibit T0=69 K in the same temperature range. A self-consistent model has been employed to calculate the various radiative and nonradiative current components in p-doped and und...

We study the effects of low-temperature capping (200-450°C) on the optical properties of GaAs/AlGaAs quantum wells. Photoluminescence measurements clearly show the formation of abundant nonradiative recombination centers in an AlGaAs capping layer grown at 200°C, while there is a slight degradation of the optical quality in AlGaAs capping layers grown at temperatures above 350°C compared to tha...

We describe the operation of a silicon optical nanocrystal memory device. The programmed logic state of the device is read optically by the detection of high or low photoluminescence intensity. The suppression of excitonic photoluminescence is attributed to the onset of fast nonradiative Auger recombination in the presence of an excess charge carrier. The device can be programmed and erased ele...

Electrically injected photonic crystal membrane light emitting microcavities with spatially localized optical gain are reported. The localization of the InGaAs quantum well inside the defect cavity of the photonic crystal allows for efficient coupling of the optical mode to the gain medium and reduces nonradiative carrier recombination. The use of a buried oxide layer under the semiconductor me...

The authors investigate the effect of oxygen implantation and rapid thermal annealing in ZnO/ZnMgO multiple quantum wells using photoluminescence. A blueshift in the photoluminescence is observed in the implanted samples. For a low implantation dose, a significant increase of activation energy and a slight increase of the photoluminescence efficiency are observed. This is attributed to the supp...

There are several challenges in the development of semiconductor lasers for the near mid-infrared region of 2-3 μm. Approaches being developed to produce lasers in this range include extending the wavelength of inter-band diode lasers which perform relatively well below ~2.5 μm. Such lasers are, however, strongly affected by increased optical losses and non-radiative Auger recombination which d...