Enhanced ammonia gas sensing by cost-effective SnO2 gas sensor: Influence of effective Mo doping

Metal oxide based semiconductors play a vital role in the development of cost-effective gas sensors. In this study, undoped and Mo-doped SnO2 films were deposited using nebulizer spray by varying Mo doping concentrations from 0 to 1.5 wt% (in steps of 0.5 wt%) at the substrate temperature of 350 degrees C. Ammonia vapour was used as the test gas. The effect of Mo doping concentration on the gas sensing ability of SnO2 films was investigated. Among the tested samples, the SnO2: Mo film with 1 wt% of Mo doping exhibits the best response (21 s) and recovery (31 s) times. The XRD results revealed the tetragonal structure and a decrease in the crystallite size upon doping. The Mo doping caused noticable changes in oxygen vacancies (as observed from PL), surface morphology, grain size and surface roughness which are found to be favourable for effective gas sensing.

Automated summary

Metal oxide based semiconductors, particularly Mo-doped SnO2 films, show promise in the development of cost-effective gas sensors. This study investigated the gas sensing ability of SnO2 films doped with different concentrations of Mo. Results showed that the SnO2:Mo film with 1wt% Mo doping exhibited the best response and recovery times. Changes in crystal structure, oxygen vacancies, surface morphology, grain size, and surface roughness caused by Mo doping were found to enhance the gas sensing performance.