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We have studied the capabilities of chemical beam epitaxy (CBE) to produce high-gain media for long-wavelength (1.5 mu m) vertical cavity surface emitting lasers (VCSELs). Using a parameter pair of low growth temperature and small V/III ratio the integrati ...
This work presents an optical characterization by luminescence and reflectivity of GaN layers grown on sapphire using MOVPE, HVPE and GSMBE. Well resolved optical spectra are obtained for each growth technique. The luminescence of Mg doped MOVPE grown GaN ...
In the present work, we theoretically investigate the intersubband relaxation of electrons in quantum well systems during photoexcitation using an ensemble Monte Carlo approach. In particular, we compare with recent experimental results by Hartig et al. (P ...
In a recent paper we measured the lateral hole diffusion in a GaAs/AlGaAs single quantum well (SQW) by a novel method. At helium temperature, we estimate a lateral hole diffusion length in the QW of 1.5 mum. However, the assumption that diffusion takes pla ...
A monolithically integrated displacement sensor has been fabricated in the GaAs/AlGaAs material system. The device is configured as a Michelson interferometer and consists of a DBR laser, a directional coupler, transparent waveguides and a photodetector. I ...
Low-frequency noise measurements have been performed in the linear range of the I-V characteristics of pseudomorphic Al0.3Ga0.7As/In0.25Ga0.75As/GaAs high electron mobility transistors (HEMTs) grown by molecular beam epitaxy with different channel thicknes ...
We present a comparison between the predictions of two theoretical models and experimental results on ultrathin GaAs layers with a thickness in the range from 1 to 8 ML embedded in bulk (AlxGa1-x)As, 0.30 less than or equal to x less than or equal to 0.34. ...
We have performed low temperature (5K) photoluminescence (PL) measurements in order to study the crystalline quality of pseudomorphic modulation-doped field effect transistors (MODFET's) grown by MBE. MODFET's based on GaAs/AlGaAs with either an InGaAs or ...
We propose a simple quantum structure which exhibits resonant tunneling under one bias and simple tunneling under the opposite one, thus acting as a rectifier. The diode consists of a single laterally-indented barrier. Due to its particular conduction-band ...
GaAs/AlxGa1-xAs multiple-quantum-well (MQW) structures with identical well thicknesses but with different Al contents x in the barrier (x almost-equal-to 0.1, 0.2, 0.45, and 1) were grown by molecular-beam epitaxy to study the impurity-induced disordering ...