Wavelength tunable electroabsorption modulated DFB baser with thin film heater
Self-organized type-II In0.55Al0.45As/Al0.50Ga0.50As quantum dots realized on GaAs(311)A
Self-organized In0.55Al0.45As/Al0.50Ga0.50As quantum dots are grown by the Stranski-Krastanow growth mode using molecular beam epitaxy on the GaAs(311)A substrate. The optical properties of type-II InAlAs/AlGaAs quantum dots have been demonstrated by the excitation power and temperature dependence of photoluminescence spectra. A simple model accoun...
Effect of In-mole-fraction in InGaAs overgrowth layer on self-assembled InAs/GaAs quantum dots
We have studied the optical and structural properties of InAs/GaAs QDs covered by InxGa1-xAs (0 less than or equal to x less than or equal to 0.3) layer using transmission electron microscopy, photoluminescence (PL) spectra and atomic force microscopy. We find that the strain reduces in the growth direction of InAs islands covered by InGaAs instead...
X-ray double-crystal characterization of the strain relaxation in GaAs/GaNxAs1-x/GaAs(001) sandwiched structures
An X-ray diffraction method, estimating the strain relaxation in an ultrathin layer, has been discussed by using kinematic and dynamical X-ray diffraction (XRD) theory. The characteristic parameter Delta Omega, used as the criterion of the strain relaxation in ultrathin layers, is deduced theoretically. It reveals that Delta Omega should be indepen...
Structural and photoluminescence properties of In-0.9(Ga/Al)(0.1)As self-assembled quantum dots on InP substrate
Self-assembled In0.9Ga0.1As, In0.9Al0.1As, and InAs quantum dots (QD) were fabricated in an InAlAs matrix lattice-matched to an InP substrate by molecular beam epitaxy. Preliminary characterizations were performed using transmission electron microscopy, photoluminescence, and reflection high-energy electron diffraction. Experimental results reveal ...
Conduction band offset and electron effective mass in GaInNAs/GaAs quantum-well structures with low nitrogen concentrati...
We have investigated the optical transitions in Ga1-yInyNxAs1-x/GaAs single and multiple quantum wells using photovoltaic measurements at room temperature. From a theoretical fit to the experimental data, the conduction band offset Q(c), electron effective mass m(e)*, and band gap energy E-g were estimated. It was found that the Q(c) is dependent o...
Investigation on InGaAs/InAlAs quantum cascade lasers
The preparation and main characteristics of the InGaAs/InAlAs quantum cascade laser were given. The device has a reinforced ridge waveguide structure. The threshold current obtained at 80K is about 0. 5A, and the corresponding threshold current density is about 5kA/cm(2).
Effect of InxGa1-xAs (0
We report the effect of InchiGa1-chiAs (0 less than or equal to chi less than or equal to0.4) capping layer on photoluminescence (PL) properties of 1.3 mum wavelength self-assembled InAs quantum islands, which are formed via depositing 3.5 monolayers (ML) InAs on GaAs (1 0 0) substrate by molecular beam epitaxy (MBE). Compared with the InchiGa1-chi...
Optical properties of InGaAs quantum dots formed on InAlAs wetting layer
We have fabricated a new self-assembled quantum dot system where InGaAs dots are formed on InAlAs wetting layer and embedded in GaAs matrix. The low-temperature photoluminescence and atomic force microscopy measurements confirm the realization of the structure. In contrast to traditional InAs/Ga(Al)As quantum dots, the temperature dependence of the...
Properties and turning of intraband optical absorption in InxGa1-xAs/GaAs self-assembled quantum dot superlattice
We investigated properties of intraband absorption in In-x Ga1-xAs quantum dots (QDs) superlattice. Energy levels in conduction band in QDs were calculated for a cone-shaped quantum dot associated with coupling between QDs in the framework of the effective-mass envelope-function theory. Theoretical results demonstrated that energy levels in conduct...
