C. Sartel

Wurtzite to zinc blende phase transition in GaAs nanowires induced by epitaxial burying.

We bury vertical free-standing core-shell GaAs/AlGaAs nanowires by a planar GaAs overgrowth. As the nanowires get buried, their crystalline structure progressively transforms: whereas the upper emerging part retains its initial wurtzite structure, the buried part adopts the zinc blende structure of the burying layer. The burying process also suppresses all the stacking faults that existed in the wurtzite nanowires. We consider two possible mechanisms for the structural transition upon burying, examine how they can be discriminated from each other, and explain why the transition is favorable.

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.

Advances in III-V Semiconductor Nanowires and Nanodevices

Description: Semiconductor nanowires exhibit novel electronic and optical properties due to their unique onedimensional structure and quantum confinement effects. In particular, III-V semiconductor nanowires have been of great scientific and technological interest for next generation optoelectronic devices including transistors, light emitting diodes, lasers, photodetectors, and solar cells. Advances in III-V Semiconductor Nanowires and Nanodevices is an account of recent progress in the synthesis, characterization, physical properties, device fabrication, and applications of binary compound and ternary alloy III-V semiconductor nanowires. Each chapter is prepared by renowned experts in the field, describing the current state of knowledge and key areas of research. The book is written at the expert level, but also serves as a guide for researchers or graduate students aiming to enter semiconductor research.

Semiconductor nanowires in InP and related material systems: MBE growth and properties

In this work, we report on the Au-assisted MBE of various InP and related material NWs on InP(111)B substrates. The influence of growth conditions on the InAsP insertion geometry and composition in InP nanowire is evidenced. Ex-situ thermal annealing produces significant changes to the PL spectra of these heterostructures. It is shown that InP/InAsP/InP heterostructures are well suited for fabrication of emitters in the telecommunication wavelength range 1.3-1.55 mum.

Lateral ordering of GaAs nanowhiskers on GaAs(111)As and GaAs (110) surfaces during molecular-beam epitaxy

Possibilities of obtaining laterally ordered arrays of GaAs nanowhiskers on GaAs (110) and GaAs(111)As surfaces during the molecular beam epitaxy are considered. As in the case of the GaAs(111)As substrate, nanowhiskers are formed in the hexagonal phase on the GaAs(110) surface, which is also confirmed by the patterns of the reflection high-energy electron diffraction (obtained during the growth of nanowhiskers) and by the photoluminescence spectra.