Ultra-sensitive NO2 sensor based on vertically aligned SnO2 nanorods deposited by DC reactive magnetron sputtering with glancing angle deposition technique

Highly responsive NO2 gas sensors at low operating temperature based on tin dioxide (SnO2) nanorods were successfully developed by DC reactive magnetron sputtering with the glancing angle deposition technique. Characterization results by grazing incident X-ray diffraction (GIXRD) and field-emission scanning electron microscopy (FE-SEM) showed that the as-deposited and annealed SnO2 nanorod structures exhibited rutile phase and crystallinity was improved after annealing at 300 and 400 degrees C. The gas-sensing results indicated that nanorod structure and annealing treatment provide significant improvement on NO2 response and selectivity against H-2, H2S, ethanol and CO. As a result, 400 degrees C-annealed SnO2 nanorods exhibited a very high NO2 response of 5310 to 5 ppm NO2 at the optimal operating temperature of 150 degrees C. Thus, SnO2 nanorod prepared by sputtering with GLAD is a promising candidate for ultra sensitive and selective NO2 detection. (C) 2015 Elsevier B.V. All rights reserved.