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

Abstract

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 6.2nm. ZnO film was highly oriented along the c-axis perpendicular to the PS layer. The average crystallite size was 17.06nm for the PS layer and 17.94nm 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 605nm were due to the ZnO nanocrystalline film, and the third peak at 637.5nm was due to the nanocrystalline PS layer.