The Role of Surface Energies and Chemical Potential during Nanowire Growth

• Published in: Nano letters 2011-03, Vol.11 (3), p.1259-1264
• Main Authors: Algra, Rienk E, Verheijen, Marcel A, Feiner, Lou-Fé, Immink, George G. W, Enckevort, Willem J. P. van, Vlieg, Elias, Bakkers, Erik P. A. M
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Quantum wires; Structure of solids and liquids; crystallography
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl104267p

We present an approach to quantitatively determine the magnitudes and the variation of the chemical potential in the droplet (Δμ), the solid−liquid (γSL) and the liquid−vapor (γLV) interface energies upon variation of the group III partial pressure during vapor−liquid−solid−growth of nanowires. For this study, we use GaP twinning superlattice nanowires. We show that γLV is the quantity that is most sensitive to the Ga partial pressure (p Ga), its dependence on p Ga being three to four times as strong as that of γSL or Δμ, and that as a consequence the surface energies are as important in determining the twin density as the chemical potential. This unexpected result implies that surfactants could be used during nanowire growth to engineer the nanowire defect structure and crystal structure.