The Fabrication of PSi/ZnO Nanostructures as Chemical Sensors for the Detection of Ethanol in Solution Using an Electrochemical Impedance Technique

Abstract

In this work, porous silicon (PSi) was prepared by electrochemical etching and used as a template for ZnO nanostructures. ZnO nanostructures were grown using the catalytic immersion method at different molar ratio concentrations of the precursor and stabilizer. The ZnO nanostructures were analyzed using FESEM and photoluminescence (PL) spectrometry, before tested with ethanol solution. The population of the ZnO nanostructures on PSi increased with the concentration and followed the surface morphology of PSi. The photoluminescence spectra of ZnO show two dominant peaks in the UV and visible regions. When the concentration of the precursor increased, the PL peaks in the visible region (630 nm) shifted towards the blue region of the spectrum. The PSi/ZnO nanostructure chemical sensor has a large surface area, reversing sensor and fast response in ethanol. The performance of the sensor was affected by the morphology and defect structures of the ZnO nanostructures layer.