Abstract

We explain the composition of ternary nanowires nucleating from a quaternary liquid melt. The model we derive describes the evolution of the solid composition from the nucleated-limited composition to the kinetic one. The effect of the growth temperature, group V concentration and Au/III concentration ratio on the solid-liquid dependence is studied. It has been shown that the solid composition increases with increasing temperature and Au concentration in the droplet at the fixed In/Ga concentration ratio. The model does not depend on the site of nucleation and the geometry of monolayer growth and is applicable for nucleation and growth on a facet with finite radius. The case of a steady-state (or final) solid composition is considered and discussed separately. While the nucleation-limited liquid-solid composition dependence contains the miscibility gap at relevant temperatures for growth of InxGa1−xAs NWs, the miscibility gap may be suppressed completely in the steady-state growth regime at high supersaturation. The theoretical results are compared with available experimental data via the combination of the here described solid-liquid and a simple kinetic liquid-vapor model.

Highlights

  • Considering the current level of technology, one route to further progress is the design and application of nanostructured materials with controlled functional properties

  • A tremendous number of possible materials have opened up attractive opportunities for the control of their physical properties and enabled the fabrication of materials combinations difficult to achieve in bulk

  • The majority of NWs have been synthesized by both metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) methods via the vapor-liquid-solid mechanism [7] owing to its versatility and possibility to control the NW composition [8], crystal structure [9], morphology [10], growth direction [11], twinning [12] and kinking [13]

Read more

Summary

Introduction

Considering the current level of technology, one route to further progress is the design and application of nanostructured materials with controlled functional properties. The composition in nucleation-limited NW growth is given by a saddle point corresponding to a maximum of the formation energy in the nucleus size and a minimum in its composition [22,29] It has been shown [22,30] that in this case, the interactions between the components in the liquid phase requires the prevalence of one element over another in the liquid in order to tune the solid composition in a wide range. After nucleation, atoms of the group V elements in the droplet are consumed quickly to complete the monolayer, after that its concentration restores and the cycle repeats If this is the case, the liquid-solid composition dependence can be simulated within the developed model if the dependence of the group V concentration on the nucleus size is known (from experiment or by model fitting).

Steady State Composition
Evolution of the Solid Composition
Comparison of Theory and Experiment
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call