Al-Doping Effect on the Surface Morphology of ZnO Films Grown by Reactive RF Magnetron Sputtering


Zinc oxide (ZnO) and aluminum-doped zinc oxide (ZnO:Al) thin films were deposited onto glass and silicon substrates by RF magnetron sputtering using a zinc-aluminum target. Both films were deposited at a growth rate of 12.5 nm/min to a thickness of around 750 nm. In the visible region, the films exhibit optical transmittances which are greater than 80%. The optical energy gap of ZnO films increased from 3.28 eV to 3.36 eV upon doping with Al. This increase is related to the increase in carrier density from 5.9 × 1018 cm-3 to 2.6 × 1019 cm-3. The RMS surface roughness of ZnO films grown on glass increased from 14 to 28 nm even with only 0.9% at Al content. XRD analysis revealed that the ZnO films are polycrystalline with preferential growth parallel to the (002) plane, which corresponds to the wurtzite structure of ZnO.

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E. Pereira da Silva, M. Chaves, G. Junior da Silva, L. Baldo de Arruda, P. Lisboa-Filho, S. Durrant and J. Bortoleto, "Al-Doping Effect on the Surface Morphology of ZnO Films Grown by Reactive RF Magnetron Sputtering," Materials Sciences and Applications, Vol. 4 No. 12, 2013, pp. 761-767. doi: 10.4236/msa.2013.412096.

Conflicts of Interest

The authors declare no conflicts of interest.


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