Optimization of Deposition Parameters of SnO<sub>2</sub> Particles on Tubular Alumina Substrate for H<sub>2</sub> Gas Sensing

Abstract

Resistive gas sensors, which are widely used for the detection of various toxic gases and vapors, can be fabricated in planar and tubular configurations by the deposition of a semiconducting sensing layer over an insulating substrate. However, their deposition parameters are not often optimized to obtain the highest sensing results. Here, we have investigated the effect of deposition variables on the H-2 gas sensing performance of commercially available SnO2 particles on tubular alumina substrate. Utilizing a tubular alumina substrate equipped with gold electrodes, we varied the number of deposited layers, rotational speed of the substrate, and number of rotations of the substrate on the output of the deposited sensor in terms of response to H-2 gas. Additionally, the effect of annealing temperatures (400, 500, 600, and 700 degrees C for 1 h) was investigated. According to our findings, the optimal conditions for sensor fabrication to achieve the best performance were the application of one layer of the sensing material on the sensor with ten rotations and a rotation speed of 7 rpm. In addition, annealing at a lower temperature (400 degrees C) resulted in better sensor performance. The optimized sensor displayed a high response of similar to 12 to 500 ppm at 300 degrees C. This study demonstrates the importance of optimization of deposition parameters on tubular substrates to achieve the best gas sensing performance, which should be considered when preparing gas sensors.