Understanding the defect chemistry of tin monoxide
Citation:
Allen, J.P., Scanlon, D.O., Piper, L.F.J., Watson, G.W., Understanding the defect chemistry of tin monoxide, Journal of Materials Chemistry C, 1, 48, 2013, 8194-8208Download Item:
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Abstract:
Tin monoxide has garnered a great deal attention in the recent literature, primarily as a transparent p-type
conductor. However, due to its layered structure (dictated by non-bonding dispersion forces) simulation
via
density functional theory often fails to accurately model the unit cell. This study applies a PBE0-vdW
methodology to accurately predict both the atomic and electronic structure of SnO. Empirical van der
Waals corrections improve the structure, with the calculated
c
/
a
ratio matching experiment, while the
PBE0 hybrid-DFT method gives accurate band gaps (0.67 and 2.76 eV for the indirect and direct band
gaps) and density of states which are in agreement with experimental spectra. This methodology has
been applied to the simulation of the native intrinsic defects of SnO, to further understand the
conductivity. The results indicate that n-type conductivity will not arise from intrinsic defects and that
donor doping would be necessary. For p-type conduction, the Sn vacancy is seen to be the source, with
the 0/
1 transition level found 0.39 eV above the valence band maximum. By considering the
formation energies and transition levels of the defects at di
ff
erent chemical potentials, it is found that
the p-type conductivity is sensitive to the O chemical potential. When the chemical potential is close to
its lowest value (
2.65 eV here), the oxygen vacancy is stabilized which, whilst not leading to n-type
conduction, could reduce p-type conduction by limiting the formation of hole states.
Sponsor
Grant Number
Engineering and Physical Sciences Research Council (EPSRC)
EP/F067496
Science Foundation Ireland (SFI)
06/IN.1/I92/EC07
Science Foundation Ireland (SFI)
06/IN.1/I92
Author's Homepage:
http://people.tcd.ie/watsongDescription:
PUBLISHED
Author: WATSON, GRAEME
Type of material:
Journal ArticleCollections:
Series/Report no:
Journal of Materials Chemistry C1
48
Availability:
Full text availableKeywords:
Tin monoxideDOI:
http://dx.doi.org/10.1039/c3tc31863jLicences: