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Growth and structural characterization of GaP-GaPSb nanowires

Stjärnemyr Ghidini, Dario LU (2012) PHYM01 20112
Atomic Physics
Abstract
In this thesis epitaxial growth of Ga(P1-xSbx) and analysis by electron microscopy are presented. To the authors knowledge Ga(P1-xSbx)has not been grown in the form of nanowires before and the main motivation of this work is to investigate the possibility of overcoming the miscibility gap (1-99%) in nanostructures. The goal of this project is to gain a better understanding of the general behavior of Sb-based materials (precursors) in Metal-Organic Vapor Phase Epitaxy (MOVPE) growth system and its influence on the growth of Sb-containing compounds. Our findings can be used to improve the understanding of growth and enhance the level of control of other Sb-containing binary and ternary material systems. The nanowires were analyzed by both... (More)
In this thesis epitaxial growth of Ga(P1-xSbx) and analysis by electron microscopy are presented. To the authors knowledge Ga(P1-xSbx)has not been grown in the form of nanowires before and the main motivation of this work is to investigate the possibility of overcoming the miscibility gap (1-99%) in nanostructures. The goal of this project is to gain a better understanding of the general behavior of Sb-based materials (precursors) in Metal-Organic Vapor Phase Epitaxy (MOVPE) growth system and its influence on the growth of Sb-containing compounds. Our findings can be used to improve the understanding of growth and enhance the level of control of other Sb-containing binary and ternary material systems. The nanowires were analyzed by both Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In order to get chemical composition, X-ray Energy Dispersive Spectroscopy (EDS) was performed in combination with TEM.

The results of the growth experiments indicate that the incorporation of Sb into a GaP-based matrix is limited when attempting the growth of ternary nanowires grown on a GaP stem. Within this study, the growth conditions of the experiments were pushed towards the technical limit of the machine setup (the molar flows were maximized and minimized, respectively) and we found indications that successful growth of ternary Ga(P1-xSbx) nanostructures with variable Sb content 0<x<1 might take place at even more extreme conditions. The presence of Sb-based species in the growth system has induced up to 90% reduction of the growth rate of the nanowires and it is likely due to Sbs surfactant and surface wetting properties. Further, the growths of Ga(P1-xSbx) performed with a ratio between P and Sb molar fractions lower than 2:1 have shown deviations from the standardly found AuxGa1-x particle composition and resulted in the formation of a two-phased particle with a second gold phase-AuSb2. This project has shown previously unknown properties of Sb and Sb-containing ternaries and has opened up the material system for further investigations. (Less)
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author
Stjärnemyr Ghidini, Dario LU
supervisor
organization
course
PHYM01 20112
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Material Science, Nanowire, GaPSb
language
English
id
2493389
date added to LUP
2012-11-28 22:30:02
date last changed
2012-11-28 22:30:02
@misc{2493389,
  abstract     = {In this thesis epitaxial growth of Ga(P1-xSbx) and analysis by electron microscopy are presented. To the authors knowledge Ga(P1-xSbx)has not been grown in the form of nanowires before and the main motivation of this work is to investigate the possibility of overcoming the miscibility gap (1-99%) in nanostructures. The goal of this project is to gain a better understanding of the general behavior of Sb-based materials (precursors) in Metal-Organic Vapor Phase Epitaxy (MOVPE) growth system and its influence on the growth of Sb-containing compounds. Our findings can be used to improve the understanding of growth and enhance the level of control of other Sb-containing binary and ternary material systems. The nanowires were analyzed by both Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In order to get chemical composition, X-ray Energy Dispersive Spectroscopy (EDS) was performed in combination with TEM.

The results of the growth experiments indicate that the incorporation of Sb into a GaP-based matrix is limited when attempting the growth of ternary nanowires grown on a GaP stem. Within this study, the growth conditions of the experiments were pushed towards the technical limit of the machine setup (the molar flows were maximized and minimized, respectively) and we found indications that successful growth of ternary Ga(P1-xSbx) nanostructures with variable Sb content 0<x<1 might take place at even more extreme conditions. The presence of Sb-based species in the growth system has induced up to 90% reduction of the growth rate of the nanowires and it is likely due to Sbs surfactant and surface wetting properties. Further, the growths of Ga(P1-xSbx) performed with a ratio between P and Sb molar fractions lower than 2:1 have shown deviations from the standardly found AuxGa1-x particle composition and resulted in the formation of a two-phased particle with a second gold phase-AuSb2. This project has shown previously unknown properties of Sb and Sb-containing ternaries and has opened up the material system for further investigations.},
  author       = {Stjärnemyr Ghidini, Dario},
  keyword      = {Material Science,Nanowire,GaPSb},
  language     = {eng},
  note         = {Student Paper},
  title        = {Growth and structural characterization of GaP-GaPSb nanowires},
  year         = {2012},
}