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.com
November 13-15, 2017 | Las Vegas, USA
14
th
International Conference and Exhibition on
Materials Science and Engineering
RRJOMS | Volume 5 | Issue 7 | November, 2017
Cu
2
O thin films obtained from CuO films treated under an argon/dry-air microwave plasma
M. A. Badillo-Ávila, G. Torres-Delgado, R. Castanedo-Pérez, J. Márquez-Marín
and
O. Zelaya-Ángel
Centro de Investigación y de Estudios Avanzados del I.P.N., México
C
u
2
O is a promising material for solar cells, its synthesis is generally complicated, however. Pure Cu
2
O thin films can be obtained
from CuO films using an argon/dry-air plasma treatment. CuO is reduced to a form of metastable metallic copper that readily
oxidizes to Cu
2
O. Depending on different process conditions, the crystallite size of Cu
2
O can be increased and controlled. Different
groups of CuO samples, obtained by sol-gel deposition on glass, were annealed at different temperatures (
TA
), from 350 °C to 550.
To obtain Cu
2
O, CuO thin films were treated for 15, 20, 25 or 30 s, under an argon/dry-air plasma. The treatment took place at low
pressure (15 mbar), inside a quartz chamber in a home-made equipment consisting of a 1500 W microwave oven modified for this
purpose. The samples were placed on a ceramic plate that allowed both substrate sides to receive the same plasma treatment. Fluxes
of argon (60 SSCM) and dry air (60 SCCM) were controlled by mass controllers and injected continuously before, during and, after
the plasma treatment. Depending on the CuO films TA’s, gas flows and time of plasma treatment, Cu
2
O, Cu or a mixture of both were
obtained. Interestingly, pure Cu
2
O was produced only from a metastable form of metallic copper and only after the plasma treatment,
this by oxygen availability. To our knowledge, this phenomenon has not been reported before. CuO annealing temperatures showed
that Cu
2
O crystallite sizes tended to be bigger when lower TA‘s were used; wide variations in crystallite size were observed. Pure Cu2O
films of 100 nm in thickness with bandgap of 2.17 eV were obtained by a plasma treatment of 30 s. Some of the advantages of this
plasma processing are its simplicity, short time of treatment and, low cost of the home-made equipment.
mbadillo@cinvestav.mxRes. Rev. J Mat. Sci. 2017, 5:7
DOI: 10.4172/2321-6212-C1-012