36 research outputs found
Growth of Inclined GaAs Nanowires by Molecular Beam Epitaxy: Theory and Experiment
The growth of inclined GaAs nanowires (NWs) during molecular beam epitaxy (MBE) on the rotating substrates is studied. The growth model provides explicitly the NW length as a function of radius, supersaturations, diffusion lengths and the tilt angle. Growth experiments are carried out on the GaAs(211)A and GaAs(111)B substrates. It is found that 20° inclined NWs are two times longer in average, which is explained by a larger impingement rate on their sidewalls. We find that the effective diffusion length at 550°C amounts to 12 nm for the surface adatoms and is more than 5,000 nm for the sidewall adatoms. Supersaturations of surface and sidewall adatoms are also estimated. The obtained results show the importance of sidewall adatoms in the MBE growth of NWs, neglected in a number of earlier studies
MOVPE growth of wide bandgap materials containing boron B (Al) GaN for compact Ultraviolet lasers
International audienceno abstrac
BGaN materials on GaN/sapphire substrate by MOVPE using N2 carrier gas
International audienc
Microscopic defects and homogeneity investigations in 4H-SiC epitaxial wafers by UV scanning photoluminescence spectroscopy
UV scanning photoluminescence spectroscopy is applied to 4H-SiC epitaxy
characterization. In a first part, the technique is used for triangular defects
characterization. The results show that two kinds of defects are present. Some
defects are inclusion of cubic SiC which is confirmed by Raman spectroscopy.
The other ones consist of staking faults of different thicknesses acting as
quantum wells. In a second part, the effective lifetime profile is mapped for a
whole 50Â mm epitaxy using the variation of room temperature PL intensity
versus excitation intensity
GaN materials growth by MOVPE in a new-design reactor using DMHy and NH 3
International audienceno abstrac