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...

GaAs junction field-effect transistors (JFETs) are promising for deep cryogenic (<10K) readout electronics applications. This paper presents the structure and fabrication of GaAs JFETs and their performance at 4 K. It is shown that these JFETs operate normally at 4 K, with no anomalous behavior such as kinks or hysteresis. The noise voltage follows a 1 / f i dependence and is approximately 1 ~ ...

In this study we investigate the carrier relaxation dynamics in p-type doped InGaAs/GaAs quantum dots using time-integrated and time-resolved photoluminescence. The experiment shows that while a strong phonon bottleneck is observed in the undoped samples, with a 680 ps rise time of the photoluminescence intensity, the intra-dot relaxation time (31 ps) of the p-type doped samples is reduced sign...

We demonstrate a semiconductor based broadband near-field superlens in the mid-infrared regime. Here, the Drude response of a highly doped n-GaAs layer induces a resonant enhancement of evanescent waves accompanied by a significantly improved spatial resolution at radiation wavelengths around λ = 20 μm, adjustable by changing the doping concentration. In our experiments, gold stripes below the ...

The dc current gain dependence of InGaP/GaAs heterojunction bipolar transistors (HBTs) on subcollector and etch-stop doping is examined. Samples of InGaP/GaAs HBTs having various combinations of subcollector doping and etch-stop doping are grown, and large area (60 m 60 ( ) HBTs are then fabricated for dc characterization. It is found that the dc current gain has a strong dependence on the dopi...

The addition of 1% In to LEC GaAs has been reported to reduce the dislocation density in this material; similar data exists for Sb doping. Several effects have been inferred to explain these phenomena, the most prevailing one stating that the solid stoichiometry is affected by an as yet unknown mechanism. Similar postulations have been made to explain the growth of semi-insulating GaAs. A therm...

Doped catalyst-free GaAs nanowires have been grown by molecular beam epitaxy with the gallium-assisted method. The spatial dependence of the dopant concentration and resistivity have been measured by Raman spectroscopy and four point electrical measurements. Along with theoretical considerations, the doping mechanisms have been revealed. Two competing mechanisms have been revealed: dopant incor...

A InGaP/InGaAs/GaAs dual channel pseudomorphic HEMT (DCPHEMT) with interesting triple doped sheets having gate length 800nm is modeled and simulated by using 2-dimensional simulation package ATLAS from Silvaco. Different DC and microwave performances of the above device are analyzed and investigated to judge the potential of the device for highperformance digital device applications. Due to the...

The gain of p-doped and intrinsic InAs/GaAs quantum dot lasers is studied at room temperature and at 350 K. Our results show that, although one would theoretically expect a higher gain for a fixed carrier density in p-doped devices, due to the wider nonthermal distribution of carriers amongst the dots at T=293 K, the peak net gain of the p-doped lasers is actually less at low injection than tha...

In this Letter we present a microscopic theory of the extrinsic spin Hall effect based on the diagrammatic perturbation theory. Side-jump and skew-scattering contributions are explicitly taken into account to calculate the spin Hall conductivity, and we show that their effects scale as sigma(xy)SJ/sigma(xy)SS approximately (h/tau)/epsilonF, with tau being the transport relaxation time. Motivate...