SnO2 dendrites-nanowires for optoelectronic and gas sensing applications

SnO2 dendrites-nanowires were grown on Au coated Si substrates using evaporation condensation method. The morphology, structural, chemical composition and thermal analysis were examined using scanning electron microscopy, X-ray diffraction, energy dispersive analysis of X-ray and Fourier transformation infrared spectroscopy, and thermal gravimetric analysis, respectively. The optical constants, the thickness and the surface roughness of the prepared nanostructured films were determined by spectroscopic ellipsometry measurements. A three layers model was used to fit the calculated data to the experimental ellipsometric spectra. The obtained optical constants were compared with those obtained by other preparation methods. The sensing properties of the obtained SnO2 nanostructure were carried out for NO2 gas. The optimal operation temperature was 200 degrees C and the sensor sensitivity was 40, 56, 83 and 121 for 10, 15, 25 and 50 ppm, respectively. (C) 2011 Elsevier B.V. All rights reserved.