( 100) GaAs substrates with an Ag film about 45 nm thick were first annealed at 550 “C for 30 min in an Ar-flowing furnace (preannealing) . A 1 lo-nm-thick GaAs layer was then deposited on top of the preannealed (GaAs)/Ag samples, followed by an amorphous Ta-Si-N film that was deposited over the GaAs layer to serve as a cap layer to minimize the loss of As during the following annealing process...

In this study, defect-free zinc blende GaAs nanowires on Si (111) by molecular beam epitaxy (MBE) growth are systematically studied through Au-assisted vapor-liquid-solid (VLS) method. The morphology, density, and crystal structure of GaAs nanowires were investigated as a function of substrate temperature, growth time, and As/Ga flux ratio during MBE growth, as well as the thickness, annealing ...

A wet. chemical techniq~e is ~escribed for passivating air-exposed GaAs surfaces. The passivating ~ayer IS elemental arsemc WhICh forms as a result of illuminating an n-type GaAs wafer immersed ~n a ~i~ture of Hel acid and d~ionized 18 Mil water with light from a mercury vapor lamp at mtenSltles of 0.01-0.05 yY-cm. Studies using XPS, LEBD, and UPS show that the passivated surfaces have the foll...

We study the optical transition between bound-to-continuum states in InGaAs/GaAs quantum well infrared photodetector (QWIP) by analyzing two possible boundary conditions for the continuum states. InGaAs/GaAs QWIP differs from the GaAs/AlGaAs QWIP in many aspects. Comparing running wave function and Bloch wave function with experimental results, we find that Bloch wave function is the much more ...

We demonstrate high performance enhancementmode (E-mode) GaAs NMOSFETs with an epitaxial gate dielectric layer of La1.8Y0.2O3 grown by atomic layer epitaxy (ALE) on GaAs(111)A substrates. A 0.5-μm-gate-length device has a record-high maximum drain current of 336 mA/mm for surface-channel E-mode GaAs NMOSFETs, a peak intrinsic transconductance of 210 mS/mm, a subthreshold swing of 97 mV/dec and ...

The evolution of InAs quantum dot (QD) formation is studied on GaAs ring-like nanostructures fabricated by droplet homo-epitaxy. This growth mode, exclusively performed by a hybrid approach of droplet homo-epitaxy and Stransky-Krastanor (S-K) based QD self-assembly, enables one to form new QD morphologies that may find use in optoelectronic applications. Increased deposition of InAs on the GaAs...

UNLABELLED The effect of Sb spray prior to the capping of a GaAs layer on the structure and properties of InAs/GaAs quantum dots (QDs) grown by molecular beam epitaxy (MBE) is studied by cross-sectional high-resolution transmission electron microscopy (HRTEM). Compared to the typical GaAs-capped InAs/GaAs QDs, Sb-sprayed QDs display a more uniform lens shape with a thickness of about 3 ~ 4 nm r...

We present a novel, free-standing low-temperature GaAs (LT-GaAs) photoconductive switch and demonstrate its femtosecond performance. A 1-microm-thick layer of a single-crystal LT-GaAs was patterned into 5-10-microm-wide and 15-30-microm-long bars, separated from their GaAs substrate and, subsequently, placed across gold coplanar transmission lines deposited on a Si substrate, forming a photocon...

Coherent X-ray diffraction imaging at symmetric hhh Bragg reflections was used to resolve the structure of GaAs/In0.15Ga0.85As/GaAs core-shell-shell nanowires grown on a silicon (111) substrate. Diffraction amplitudes in the vicinity of GaAs 111 and GaAs 333 reflections were used to reconstruct the lost phase information. It is demonstrated that the structure of the core-shell-shell nanowire ca...