1110.6656 (Philip W. Avraam et al.)

Fermi level pinning can determine polarity in semiconductor nanorods    [PDF]

Philip W. Avraam, Nicholas D. M. Hine, Paul Tangney, Peter D. Haynes

First-principles calculations of polar semiconductor nanorods reveal that
their dipole moments are strongly influenced by Fermi level pinning. The Fermi
level for an isolated nanorod is found to coincide with a significant density
of electronic surface states at the end surfaces, which are either mid-gap
states or band-edge states. These states pin the Fermi level, and therefore fix
the potential difference across the rod. We provide evidence that this effect
can have a determining influence on the polarity of nanorods, and has
consequences for the way a rod responds to changes in its surface chemistry,
the scaling of its dipole moment with its size, and the dependence of polarity
on its composition.

View original: http://arxiv.org/abs/1110.6656