Abstract
Quasi-aligned GaN nanowire arrays have been fabricated via a thermal evaporation of the starting reactants
Ga
2
O
3
∕
Ga
N
. The GaN nanowires have uniform diameters of
∼
300
nm
, lengths up to tens of micrometers and possess a sharp six-fold symmetrical pyramidlike tip. High-resolution transmission electron microscopy (TEM) analysis indicated that majority of GaN nanowires have a preferential growth direction along the [0001] direction. Room-temperature field-emission measurement showed that the as-synthesized GaN nanowire arrays have a lower turn-on field of
7.0
V
/
μ
m
. It is believed that both the sharp tips and rough surface of GaN nanowires contribute to the excellent electron emission behavior.