We study the mutual passivation of shallow donor and isovalent N in GaAs. We find that all the donor impurities, SiGa, GeGa, SAs, and SeAs, bind to N in GaAs:N, which has a large N-induced band-gap reduction relative to GaAs. For a group-IV impurity such as Si, the formation of the nearest-neighbor SiGa-NAs defect complex creates a deep donor level below the conduction band minimum (CBM). The c...

Calculations of the tunneling magnetoresistance (TMR) of an epitaxial Fe/MgO/Fe tunneling junction attached to an n-type GaAs lead, under positive gate voltage, are presented. It is shown that for realistic GaAs carrier densities the TMR of this composite system can be more than 2 orders of magnitude higher than that of a conventional Fe/MgO/Fe junction. Furthermore, the high TMR is achieved wi...

We identified the charge carrier compensation mechanism in Te-doped GaAs with atomically resolved scanning tunneling microscopy. Three types of defects were found: tellurium donors (TeAs), Ga vacancies (VGa), and Ga vacancy–donor complexes (VGa– TeAs). We show quantitatively that the compensation in Te-doped bulk GaAs is exclusively caused by vacancy– donor complexes in contrast to Si-doped GaA...

In this letter, we show that the oscillation features sOFsd usually observed in photoreflectance sPRd spectra of GaAs-based structures grown on the n-type GaAs substrate below the GaAs fundamental gap could be eliminated completely by applying the contactless electroreflectance sCERd instead of PR. This finding confirms that the origin of OFs is the modulation of the refractive index in the sam...

In this letter, n-type doping of GaAs nanowires grown by metal-organic vapor phase epitaxy in the vapor-liquid-solid growth mode on (111)B GaAs substrates is reported. A low growth temperature of 400°C is adjusted in order to exclude shell growth. The impact of doping precursors on the morphology of GaAs nanowires was investigated. Tetraethyl tin as doping precursor enables heavily n-type doped...

We demonstrate a new source of frequency-tunable THz wave packets based on parametric down-conversion process in orientation-patterned GaAs (OP-GaAs) that produces muW-level THz average powers at the repetition rate of 100 MHz. The OP-GaAs crystal is pumped by a compact all-fiber femtosecond laser operating at the wavelength of 2 mum. Such combination of fiber laser and OP-GaAs technologies pro...

A low-temperature (LT) grown InAs epi-layer has been applied as the gate to the dual-material structure of lattice-matched InGaP on GaAs, to make a high-temperature power rectifier. The LT molecular beam epitaxy technique enables the formation of an abrupt interface between InAs and InGaP. This heterojunction rectifier utilises the strong thermal stability of the InAs=InGaP heterojunction and t...

New RF circuit techniques have overcome the distortion problems for low supply voltages. The RF IC chip-set for the 1.9 GHz Japanese Personal Handy Phone (PHP) system includes a low noise amplifier (GaAs MMIC), a mixer (GaAs MMIC), a linear power amplifier (GaAs MMIC), a T/R switch (GaAs MMIC), a 1.9 GHz direct-conversion quadrature modulator (Si LSI), and a frequency synthesizer (Si LSI). Thes...

Several oxide-GaAs heterostructures were fabricated using in situ multiple-chamber molecular beam epitaxy. The oxides include SiO2, MgO, and Ga2O3~Gd2O3!, all evaporated by an electron beam method. The SiO2 and Ga2O3~Gd2O3! films are amorphous while the MgO films are crystalline and part of the films are epitaxially grown on GaAs~100!. Among these heterostructures, the Ga2O3~Gd2O3!–GaAs shows a...

The article investigates the effect of rapid thermal annealing ternary GaAs 1-x N x /GaAs solid solutions on distribution nitrogen atoms in crystal lattice. samples are studied by photoluminescence spectroscopy and high-resolution X-ray diffractometry. Due to size electronegativity mismatch arsenic atoms, is incorporated unevenly into Options arrangement lattice before after shown. Keywords: di...