Solid-State Electronics, Vol.87, 43-50, 2013
Development of an ethanol sensor based on CBD grown ZnO nanorods
In this paper, we report on development of an ethanol sensor based on ZnO hexagonal nanorods grown by a chemical bath deposition technique. Nanorods were deposited on a SiO2 coated p-Si substrate. Nanocrystalinity, stoichiometry, and surface roughness of the nanorods were determined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). The average diameter and average length of the nanorods were found to be similar to 70 nm and similar to 500 nm, respectively. Four types of sensors structures, to investigate the effect of catalytic metal alloy electrode (Pd-Ag) and Pd nanoparticle sensitization, were fabricated. All the sensors were tested for sensing ethanol vapor in the temperature range of 27-300 degrees C. The incorporation of catalytic electrode Pd-Ag (70%) and surface modification of nanorods by Pd nanoparticle improved the ethanol sensing performance. For Pd modified nanorods (with catalytic electrode), response magnitude, response time, and recovery time was 94%, 14 s and 70 s (respectively) at 1530 ppm of ethanol (in air) at an optimum operating temperature of 200 degrees C. The dynamic range of the sensors was also found to be quite appreciable (190-1530 ppm ethanol in air). (c) 2013 Elsevier Ltd. All rights reserved.