Fe doped tin oxide was prepared by hydrothermal method and the same has been used to fabricate a thin film for sensing. Fe doped tin oxide was prepared by sol–gel dip-coating technique on the glass substrates for hydrogen sensing. The microstructure and morphology of the prepared materials were analysed by XRD and SEM analysis. The SEM images clearly show that doping can clamp down the growth of the large crystallites and can lead to large agglomeration spheres. Thin film gas sensors were formed from undoped pure SnO₂ and Fe doped SnO₂. The sensors were exposed to ammonia and ethanol gases. The responses of the sensors to 1000 ppm of hydrogen gas at different operating temperatures (25 °C – 100 °C) were studied. Results show that a good sensitivity towards hydrogen gas was obtained with Fe doped SnO₂ thin film sensor at an optimal operating temperature of 75 °C. Response time of the sensor and its stability were also studied.

Keywords: Hydrogen Sensor; SnO₂ Thin Films; Gas Sensors; Sol-Gel; Fe Doped SnO₂;