A standard Gacs11ne4sP/GaAs modulation-doped field-effect transistor (MODFET) structure and a novel Gacs11nc4sP/GaAs MODFET structure where the GacslIne4sP spacer layer was replaced by an undoped AlO,sGac,As layer were grown using a gas source molecular beam epitaxy. The Hall mobility of the novel MODFET’s structures are 6600 and 36 400 cm2/V s at room temperature and 77 K, respectively, which ...

Dark current in AIGaAs/GaAs two-dimensional electron gas charge-coupled devices (2DEG CCDs) is investigated both theoretically and experimentally. Measurement of the dark current for temperatures in the range 160 K to 360 K was performed and compared with the results of numerical modelling. It is found that thermionic-field emission of electrons from the gate to the channel is the dominant mech...

We report on the transport, magnetotransport and magnetic properties of In0.17Ga0.83As quantum well in GaAs d-doped by Mn. At low temperatures, the anomalous Hall effect was observed which detects the spin-polarized carriers. Negative magnetoresistance was found at low temperatures, which became positive at high temperature. r 2005 Elsevier B.V. All rights reserved. PACS: 72.20. i; 75.50.Gg

The two-dimensional electron gas charge-coupled device (ZDEG-CCD) structure for 111-V and other heterojunction materials is reviewed. Device design considerations for gate, insulator, and channel material parameters are presented. Optimization of ZDEG-CCD performance parameters such as well capacity, dark current, and transfer efficiency is discussed. Experimental results on AIGaAs/GaAs uniform...

A simple two-band model is suggested explaining recently reported unusual features for hopping magnetoresistance and the metal-insulator transition in 2D structures. The model implies that the conductivity is dominated by the upper Hubbard band (D-band). Experimental studies of hopping magnetoresistance for Si δ-doped GaAs/AlGaAs heterostructure give additional evidences for the model.

Articles you may be interested in MBE growth of P-doped 1.3 μm InAs quantum dot lasers on silicon Low-threshold high-quantum-efficiency laterally gain-coupled InGaAs/AlGaAs distributed feedback lasers Appl. 1.3 μm InGaAsP/InP lasers on GaAs substrate fabricated by the surface activated wafer bonding method at room temperature Appl.

The laser-induced chemical etching mechanism of Cr–O doped GaAs (1 0 0) substrate in 40% HF-H2O solution is explained by the generation of e–h pairs through defect states in the presence of sub-bandgap photon illumination by using a Nd:YAG Laser (λ ∼ 1.06 m). The central feature of the laser etching technique is pits initiation by surface defects. The etched GaAs samples are characterised by ph...

The variation of minority electron mobility with doping density in p+-GaAs has been measured with the zero-field time-of-flight technique. The results from a series of nine GaAs films doped between 1 X lOI and 8 X 10” cmm3 show the mobility decreasing from 1950 cm2 V-’ s-l at 1 X 10” cmm3 to 1370 cm2 V-l s-l at 9X 10” cmB3. For the doping range 9 x 1018-8x 1019 cme3, the decreasing trend in mob...

We advance all optical spin noise spectroscopy (SNS) in semiconductors to detection bandwidths of several hundred gigahertz by employing a sophisticated scheme of pulse trains from ultrafast laser oscillators as an optical probe. The ultrafast SNS technique avoids the need for optical pumping and enables nearly perturbation free measurements of extremely short spin dephasing times. We apply the...

Epitaxial growth of vertical GaAs nanowires on Si(111) substrates is demonstrated by metal-organic chemical vapor deposition via a vapor-liquid-solid growth mechanism. Systematic experiments indicate that substrate pretreatment, pregrowth alloying temperature, and growth temperature are all crucial to vertical epitaxial growth. Nanowire growth rate and morphology can be well controlled by the g...