Simulation of the indium profile in InGaAs/GaAs quantum-size heterostructures

A new approach to describe phenomena attendant on the growth of thin InGaAs epitaxial layers by hydride MOCVD in terms of which the boundary gas layer is considered as quasi-liquid is suggested. A numerical model for simulating the concentration profiles of the components in quantum-well heterostructures is developed. It is based on the assumption that a state close to thermodynamic equilibrium exists near the interface. The concentration profiles are simulated by jointly solving equations that describe heterogeneous equilibria and material balance at the interface. The indium profiles in InGaAs/GaAs quantum-size heterostructures are simulated at various parameters of the epitaxy process, such as temperature, initial component ratio in the gas phase, and boundary layer thickness. The results obtained agree well with the available experimental data.     

Electron-beam pumped pulsed IR semiconductor laser based on a quantum-size InGaAs/AlGaAs structure

The characteristics of the radiation of a 890-nm laser based on a quantum-size InGaAs/AlGaAs structure, pumped by a (15–26)-keV electron beam, have been studied. An output pulsed power up to 90 W with an efficiency of 3.5% is obtained from each laser end face at room temperature of the active element and a cavity length of 0.5 mm.     

Formation conditions for InAs/GaAs quantum dot arrays by droplet epitaxy under MOVPE conditions

The first stage of formation of InAs/GaAs quantum-dot heterostructures by droplet epitaxy is investigated. Factors influencing the geometrical size and density of arrays of indium nanodrops deposited by trimethylindium pyrolysis on the GaAs(100) substrate are analyzed, and the possibility of using these factors in the process of metal-organic vapor phase epitaxy (MOVPE) are studied. To refine the temperature dependence of the In evaporation rate, a computational experiment taking into account real MOVPE conditions is conducted. An ultimate change in the composition of In droplets contacting the substrate at a high temperature is estimated, and the thickness and composition of crystallizing In-Ga-As solid solution are calculated. It is shown that the size and density of the droplet array to a great extent depend on the crystallochemical structure of the substrate surface and deposition conditions.     

Tunable laser diodes for the 1250-1650 nm spectral range

A series of tunable laser diodes was developed with emission wavelength in spectral range 1250-1650 nm. This paper describes the configuration and basic characteristics at temperatures from 5 to 80 degrees C.