The effect of an initial saturation coverage of antimony on the growth of indium arsenide quantum dots on gallium arsenide has been studied during metalorganic vapor-phase epitaxy. After depositing one to two bilayers of InAs at 723 K, the samples were quenched, transferred to ultrahigh vacuum, and characterized by scanning tunneling microscopy and x-ray photoelectron spectroscopy. It has been ...

This paper examines the potential deployment of a 10 mm × 1 cadmium telluride detector for strontium-90 measurement in groundwater boreholes at nuclear decommissioning sites. Geant4 simulation was used to model borehole monitoring contaminated groundwater. It found that sensitive strontium-90, yttrium-90, caesium-137, and potassium-40 decay, some significant beta emitters Sellafield. However, d...

A design study is presented for an efficient, compact and robust device to convert the frequency of single-photons from near-infrared telecom C-band. The material platform aluminum gallium arsenide (AlGaAs)-on-insulator, with its relatively large second-order nonlinearity, used create highly confined optical modes. This can feasibly incorporate single-photon emitters such as indium (InAs) on (G...

A symmetric gain optoelectronic mixer based on an indium gallium arsenide (In0.53Ga0.47As)/indium phosphide (InP) symmetric heterojunction phototransistor structure is being investigated for chirpedAM laser detection and ranging (LADAR) systems operating in the ‘‘eye-safe” 1.55 lm wavelength range. Signal processing of a chirped-AM LADAR system is simplified if the photodetector in the receiver...

Hydrogen adsorption on the ~234! and ~432! reconstructions of gallium arsenide ~001! has been studied by internal reflectance infrared spectroscopy and ab initio cluster calculations with density-functional theory. The calculations are made on Ga5As4H11,13, Ga4As5H11,13 , and Ga7As8H19 clusters, which model the arsenicand gallium-dimer termination of the semiconductor surface. Excellent agreeme...

Gallium arsenide nanowires were synthesized by gallium-assisted molecular beam epitaxy. By varying the growth time, nanowires with diameters ranging from 30 to 160 nm were obtained. Raman spectra of the nanowire ensembles were measured. The small linewidth of the optical phonon modes agree with an excellent crystalline quality. A surface phonon mode was also revealed, as a shoulder at lower fre...

The initial growth of ~234! phosphorous islands on ~432! terraces of gallium arsenide ~001! has been studied. The islands grow anisotropically in the @110# direction with an aspect ratio of approximately 8 to 1 at moderate coverages. The distribution of island widths in the @ 1̄10# direction follows a Gaussian function. The mean width increases from 2466 to 47611 Å as the phosphorous coverage in...

Myotoxins present in Bothrops venom disrupt the sarcolemma of muscle fibers leading to the release of sarcoplasmic proteins and loss of muscle homeostasis. Myonecrosis and tissue anoxia induced by vascularization impairment can lead to amputation or motor functional deficit. The objective of this study was to investigate the dynamic behavior of motor function in mice subjected to injection of B...