Photomodification of carrier lifetime and diffusivity in AlGaN epitaxial layers

Identification and carrier dynamics of the dominant lifetime limiting defect in n 4H-SiC epitaxial layers

Spin lifetime in InAs epitaxial layers grown on GaAs

We report investigation of the spin relaxation in InAs films grown on GaAs at a temperature range from 77 K to 290 K. InAs is known to have a surface accumulation layer and the depth profile of the concentration and mobility is strongly nonuniform. We have correlated the spin relaxation with a multilayer analysis of the transport properties and find that the surface and the interface with the G...

High breakdown voltage in AlGaN/GaN HEMTs using AlGaN/GaN/AlGaN quantum-well electron-blocking layers

In this paper, we numerically study an enhancement of breakdown voltage in AlGaN/GaN high-electron-mobility transistors (HEMTs) by using the AlGaN/GaN/AlGaN quantum-well (QW) electron-blocking layer (EBL) structure. This concept is based on the superior confinement of two-dimensional electron gases (2-DEGs) provided by the QW EBL, resulting in a significant improvement of breakdown voltage and ...

Compositional modulation and optical emission in AlGaN epitaxial films

Compositional, structural, and optical properties of molecular-beam epitaxy grown AlxGa1−xN films were characterized by transmission electron microscopy TEM , x-ray diffraction, and cathodoluminescence spectroscopy. Spontaneous modulation, phase separation, and band gap reductions were observed to vary systematically with AlN mole fraction across the full alloy series. At low AlN mole fraction ...

Proximity effects of beryllium-doped GaN buffer layers on the electronic properties of epitaxial AlGaN/GaN heterostructures

AlGaN/GaN/Be:GaN heterostructures have been grown by rf-plasma molecular beam epitaxy on freestanding semi-insulating GaN substrates, employing unintentionally-doped (UID) GaN buffer layers with thicknesses, dUID, varying between 50 nm and 500 nm. We have found that the heterostructures with UID buffers thicker than 200 nm exhibit much improved Hall properties and inter-device isolation current...