Growth of Zinc Oxide Nanocombs on Porous Silicon Layer by Thermal-Evaporation Method

Abstract

Zinc oxide (ZnO) film was deposited on a porous silicon (PS) layer prepared by electrochemical etching through the thermal-evaporation method. ZnO nanocombs structure arrays were directly fabricated on the PS substrate through zinc powder evaporation, which uses a simple thermal-evaporation method without a catalyst. The ZnO nanocombs were highly oriented along the c-axis perpendicular to the PS layer. The average crystallite size of the PS and the ZnO nanocombs were 17.06 and 17.94 nm, respectively. The photoluminescence emission spectra of the ZnO nanocombs grown on the PS layer showed three emission peaks. The two peaks located at 387.5 and 605 nm were caused by the ZnO nanocombs, whereas the third peak located at 637.5 nm was caused by the PS layer. The ZnO nanocombs grown on the PS layer exhibited exceptional light trapping at wavelengths ranging from 400 to 1000 nm, which was expected to increase the efficiency of nano-electronic and nano-optical devices such as (solar cells).