Abstract
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Pure and Se-doped GaN nanowires (NWs) are synthesized on Pt-coated Si(111) substrates via
chemical vapor deposition. The GaN NWs exhibit a uniform density with an average diameter of
20–120 nm. The structure of the NWs is wurtzite hexagonal, and the growth direction is along
[0001]. Field emission measurements show that the Se-doped GaN NWs possess a low turn-on
field (2.9 V μm−1
) compared with the pure GaN NWs (7.0 V μm−1
). In addition, density
functional theory calculations indicate that the donor states near the Fermi level are mainly
formed through the hybridization between Se 4p and N 2p orbitals and that the Fermi level move
towards the vacuum level. Consequently, the work functions of Se-doped GaN NWs are lower
than those of pure GaN NWs.