Physical Review B 83, 241402(R) (2011)
Factors influencing the distribution of charge in polar nanocrystals
Philip W. Avraam, Nicholas D. M. Hine, Paul Tangney and Peter D. Haynes
Department of Physics and Department of Materials, Imperial College London,
Exhibition Road, London SW7 2AZ, United Kingdom
We perform first-principles calculations of wurtzite GaAs nanorods to
explore the factors determining the charge distribution in polar
nanostructures. We show that both the direction and magnitude of the
dipole moment d of a nanorod, and the electic field, depend
sensitively on how its surfaces are terminated and not strongly on the
spontaneous polarization of the underlying lattice. We identify two
physical mechanisms by which d is controlled by the surface
termination, and we show that the excess charge on the nanorod ends is
not strongly localized. We discuss the implications of these results
for tuning nanocrystal properties, and for their growth and assembly.
Last updated: 2 June 2011