Nanocrystalline ZnO film grown on porous silicon layer by radio frequency sputtering system

Nanocrystalline zinc oxide (ZnO) film was successfully synthesized on a porous silicon (PS) layer using radio frequency sputtering system. The PS layer was prepared by electrochemical etching method, resulting in 91% porosity with an average pore diameter of 6.2 nm. ZnO film was highly oriented along the c-axis perpendicular to the PS layer. The average crystallite size was 17.06 nm for the PS layer and 17.94 nm for the ZnO film. The low value of the tensile strain 0.36% revealed ZnO nanocrystalline film preferred to grow along the c-axis. The photoluminescence emission spectra of the ZnO/PS layers exhibited three emission peaks: two peaks located at 387.5 and 605 nm were due to the ZnO nanocrystalline film, and the third peak at 637.5 nm was due to the nanocrystalline PS layer. (C) 2011 Elsevier B.V. All rights reserved.