Papers by Keyword: AlGaAs

Abstract: The results of the presented studies demonstrate the possibility of using two and three component solid solutions, based on elements of the A3B5 groups, as thin barrier layers to cover an array of structured InAs quantum dots for photoactive heterointerfaces of solar energy. When using three-component solid solutions for QD barrier layers, a decrease in the thermionic generation in the near infrared spectrum and a decrease in the dark current of the heterointerface are obtained.

Abstract: It is known that the rate of introduction of radiation defects into the Schottky barrier of GaAs and InP diodes depends on the presence of the electric field. The main aim of this research is to study the influence of the built-in electric field at the p-n junction on the resistance of dual AlGaAs heterostructure IR-LEDs under gamma rays irradiation. It is determined that the rate of defects introduction in the presence of built-in electric field or reverse bias at p-n junction is considerably less than the rate of defects introduction into the neutral region without electric field. Then the possible ways of improving the radiation resistance of infrared LEDs are considered.

Abstract: In this paper we present the results of investigation of the power mode influence on the resistance to fast neutron irradiation of IR-LEDs based on AlGaAs heterostructures. The investigation shows that there are 2 stages of LED emissive power lowering. At the first stage the emissive power decreases due to reorganization of existing defective structure. At the second stage it happens as the result of radiation defects introduction. The rate of defects introduction that influences the emissive power lowering at the first stage in the space charge region of the embedded p-n junction is higher than in the neutral region. The forward current flowing under irradiation results in partial annealing of introduced defects and consequently to resistance growth at the first stage of emissive power lowering. The LED power mode doesn’t contribute essentially to the power lowering at the second stage while observed difference is due to decrease of contribution of the first stage to the whole process of emissive power lowering.

Abstract: The Hall resistivity in the layers of Al_xGa_1-xAs/Al_0.32Ga_0.68As is found to show plateaus at certain fractions which depend on the effective charge. The Hall resistivity formula ρ_xy=h/e² has been modified to ρ_xy=h/[(1/2) ge²] so that the effective charge of the electron becomes, e*=(1/2) ge. The plateaus occur at the effective charge determined by g = (2j+1)/(2l+1). Some of the plateaus are explained to arise from the g values while some others require the use of Landau levels. The flux quantization is modified to include the effect of spin. When the samples are doped with aluminium, the clusters of Al atoms occur in the GaAs resulting into electron clusters in which the spin is NS with S=1/2 and N=101. The electron clusters form a temperature dependent plateau in the Hall resistivity.

Abstract: High-performance 785 nm wavelength super-luminescent diodes (SLDs) with ring cavity were fabricated. The maximum output power of 100 mW was obtained in continuous wave (CW) mode under room temperature. The full width at half maximum (FWHM) of the emission spectrum was 24 nm.