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A new method for the formation of three-dimensional quantum-dimensional InGaP(As) islands is proposed, which consists in replacing phosphorus with arsenic in an InGaP layer deposited on GaAs directly during epitaxial growth. It is shown that the replacement of phosphorus with arsenic results in formation of three-dimensional islands in the thin InGaP layer. At room temperature, these islands emit light in the spectral range of 0.95–0.97 µm. The estimated density of the islands is 1.3 × 1010 cm–2. [ABSTRACT FROM AUTHOR]

We have studied heterostructures based on short-period InGaAs/InGaAlAs superlattices (SLs) manufactured by molecular-beam epitaxy on InP substrates, intended for use as active regions in vertical-cavity surface-emitting lasers operating in a 1.3-μm spectral range. The heterostructures were characterized by measuring photoluminescence (PL) emission and X-ray diffraction. It is established that variation of the ratio of quantum-well and barrier-layer thicknesses in the SL allows controlled shift of the PL peak position for lasing in the 1.3-μm range at almost constant PL efficiency. [ABSTRACT FROM AUTHOR]

The results of experiments on the fabrication (by molecular-beam epitaxy) and investigation of the heterostructures of a two-frequency quantum-cascade laser produced on the basis of a heteropair of In0.53Ga0.47As/Al0.48In0.52As solid solutions on an InP substrate are presented. The heterostructures contained quantum cascades emitting at a wavelength of 9.6 μm and cascades emitting at a wavelength of 7.6 μm. The high structural quality of the fabricated heterostructures is shown. The spontaneous emission and lasing spectra are investigated and the multimodal laser generation of stripe lasers at a wavelength of 7.6 μm is demonstrated. [ABSTRACT FROM AUTHOR]

Epitaxial GaAs layers containing InAs semiconductor quantum dots and As metal quantum dots are grown by molecular beam epitaxy. The InAs quantum dots are formed by the Stranskii-Krastanow mechanism, whereas the As quantum dots are self-assembled in the GaAs layer grown at low temperature with a large As excess. The microstructure of the samples is studied by transmission electron microscopy. It is established that the As metal quantum dots formed in the immediate vicinity of the InAs semiconductor quantum dots are larger in size than the As quantum dots formed far from the InAs quantum dots. This is apparently due to the effect of strain fields of the InAs quantum dots upon the self-assembling of As quantum dots. Another phenomenon apparently associated with local strains around the InAs quantum dots is the formation of V-like defects (stacking faults) during the overgrowth of the InAs quantum dots with the GaAs layer by low-temperature molecular beam epitaxy. Such defects have a profound effect on the self-assembling of As quantum dots. Specifically, on high-temperature annealing needed for the formation of large-sized As quantum dots by Ostwald ripening, the V-like defects bring about the dissolution of the As quantum dots in the vicinity of the defects. In this case, excess arsenic most probably diffuses towards the open surface of the sample via the channels of accelerated diffusion in the planes of stacking faults. [ABSTRACT FROM AUTHOR]