In this communication, we show that ultrafast photoconductors based on low-temperature-grown Gallium Arsenide material exhibit photoresponse values reaching 11 mA/W under 1550 nm CW excitation. This is obtained by using an optical microcavity based on a buried metal layer acting as back reflecting mirror and a top grating electrode in order to impr...
In this work, Molecular Beam Epitaxy (MBE) grown tunnel junctions (TJs) based on GaAs(Sb)(In) materials are experimentally and numerically studied. From simple GaAs TJs grown with various n-doping levels, we develop a semi-classical interband tunneling model able to quantify the magnitude of the tunneling current density, which shows that direct in...
We report on the realization of AlGaSb/InAs Esaki tunnel diodes on GaSb (001) substrate. Selective area molecular beam epitaxy of InAs is used to define the area of the diodes down to submicron dimensions. A peak current density up to 1.3 MA/cm2 is achieved.
We report a photoconductive switch using low temperature grown GaNAsSb as the active material. The GaNAsSb layer was grown at 200 °C by molecular beam epitaxy in conjunction with a radio frequency plasma-assisted nitrogen source and a valved antimony cracker source. The low temperature growth of the GaNAsSb layer increased the dark resistivity of t...
We report on AlGaN/GaN multi-quantum-well structures displaying intersubband absorption in the THz spectral range. First, we theoretically analyze the weaknesses of the state-of-the-art GaN-based step-quantum-well architecture from an optoelectronic standpoint. We then propose a modified geometry with improved structural robustness considering the ...
We demonstrate quantitative ballistic electron magnetic microscopy (BEMM) imaging of simple model Fe(001) nanostructures. We use in situ nanostencil shadow mask resistless patterning combined with molecular beam epitaxy deposition to prepare under ultra-high vacuum conditions nanostructured epitaxial Fe/Au/Fe/GaAs(001) spin-valves. In this epitaxia...
This work studies the effect of the growth temperature on the morphology and emission characteristics of self-assembled InGaN nanocolumns grown by plasma assisted molecular beam epitaxy. Morphology changes are assessed by scanning electron microscopy, while emission is measured by photoluminescence. Within the growth temperature range of 750 to 650...
