Effects of Target Composition on the Optical Constants of uC Sputtered ZnO:AI Thin Films
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Date
2012Author
Samuel, B.
VIlyuka, N.R
Sarmiji, E
Kivaisi, R. T
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AI-doped lJlO thin films were deposited from lnO:AI ceramic and Zn.Al meial alloy targets, Deposition
took place in Ar and Ar + O2 atmosphere for lnOAI and ZnAl targets: respectively, using DC
magnetron sputtering. Transmittance (T) measurements showed T> SCYl'o in visible region with good NIR
shielding, The band gap energy ranged from 3.34 to 3,44 eV and 3.39 to 3.46 eV for films prepared from
alloy and ceramic targets, respectively. The films with lowest elecuical sheet resistance of ] 0 0./0 and
highest values of mobility and carrier concentration of 159 cm:/V~ and 2.98 x 1021 CI11·3respectively,
were obtained using alloy- target at a substrate temperature of 200 "C. However, films prepared from
ceramic target at 3 substrate temperature of 300°C revealed the: lowest sheet resistance of 32 D./o: with
the highest values of Inability and charge carrier concentration of l-l.] CI1l1;VS and 1.92 x ] 010 cm-]
respectively Optical spectra of the films were fitted (0 SCOUT software in order to determine the
refractive index, 11 and extinction coefficient. k. Generally, the calculated 11 and k in the visible part of the
solar spectrum for different samples; ranged from ].59 (0 2.2 and ()OOO I3 to 0.0 I94 respectively, which
are in agreement with results calculated using other methods
Key words: DC Magnetron Sputtering, Optical Constants, Transparent Conducting Oxides (TCO)