Zinc Oxide Nanowire Films: Solution Growth, Defect States and Electrical Conductivity - Advanced Materials for Agriculture, Food and Environmental Safety - page 481

simultaneously have good electrical conductor. It is also observe that TEP
of semiconductor material depends on the electron and hole asymmetries
at the Fermi level, and is very sensitive to small changes in scattering rate
and the density of states at the Fermi level [204]. Recent studies are shown
that ZnO can be potential material for thermoelectric energy generators
due to its excellent stability at elevated temperatures and good electrical
conductivity [16, 204-207]. However, high lattice thermal conductivity is
the main barrier to its practical applications. In order to increase phonon
scattering, amorphous ZnO thin-i lm device has been tried, [205]. Doping
of metallic elements enhances conductivity of ZnO, but the ef ect on pho-
non scattering is found to be mixed. h eoretical results have shown that
the thermoelectric performance of the Ga-doped ZnO is strongly depen-
dent on the Ga contents, and ZnO NW has demonstrated an increase by
a factor of 2.5 at Ga content of 0.04, compared with pure ZnO NWs i g-
ure of merit [207]. It has been seen that phonon scattering is promoted
by Al-induced grain rei nement and it was concluded that Al-doped non-
nanostructured ZnO is one of the best n-type thermoelectric oxides [17].
h e thermoelectric performance of ZnO is largely dependent on oxygen
vacancies, hence manipulation of defect states/vacancies in ZnO nanowire
can improve i gure of merit in nanowire array-based devices in order to
provide a high order of ei ciency. h erefore new device design needs to
be address.

References

1. U. Özgür, Y.I. Alivov, C. Liu, A. Teke, M.A. Reshchikov, S. Doğan, V. Avrutin,
S.-J. Cho, H. Morkoç, Journal of Applied Physics , Vol. 98, p. 041301, 2005.
2. A. Janotti, C.G. Van de Walle, Reports on Progress in Physics , Vol. 72, p.
126501, 2009.
3. C. Klingshirn, vol.8, p.782 , 2008.

4. V. Bhosle, J. Narayan, Journal of Applied Physics , Vol. 100, p. 093519, 2006.
5. C.G. Van de Walle, Physica B: Condensed Matter , Vol. 308-310, p. 899, 2001.
6. B.J. Jin, S.H. Bae, S.Y. Lee, S. Im, Materials Science and Engineering: B , Vol.
71, p. 301, 2000.
7. A. Mansingh, and V. Gupta, Physical Review B , Vol. 49, p. 1989, 1994.
8. I. Gonzalez-Valls, M. Lira-Cantu, Energy & Environmental Science , Vol. 2, p.
19, 2009.
9. M. Law, L.E. Greene, J.C. Johnson, R. Saykally, P. Yang, Nature Materials , Vol.
4, p. 455, 2005.
10. L. Li, T. Zhai, Y. Bando, D. Golberg, Nano Energy , Vol. 1, p. 91, 2012.

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