Chemically sprayed pristine and Cd ²⁺ incorporated Co₂SnO₄ thin films for low ppm level enhanced chemi - resistive...

The surge in hazardous volatile organic liquid emissions driven by the rapid growth of the manufacturing industry has compelled a rising demand for gas sensors, which exhibit remarkable sensitivity, selectivity, and room temperature operation. Ternary metal oxide spinel has indeed garnered significant attention in chemi-resistive gas sensors due to their large reactive surface area, physicochemical, and other unique properties. In this work, we have studied chemically sprayed pristine and Cd ²⁺ incorporated Co₂SnO₄ thin film as a sensing layer under room temperature (300 K) conditions. The 5 wt% Cd ²⁺ incorporated Co₂SnO₄ films unveiled a high sensor response to dimethylamine (DMA) gas (S = I_gas/I_air = 6153 at 1 ppm), which was boosted by 8.89-fold times compared to pristine Co₂SnO₄ film, due to the large reactive surface area and enhanced defective oxygen vacancies. It has superior selectivity towards DMA gas, good response time (154 s) / recovery time (90 s), superior pro-longevity (S = 6138) after 60 days, stable repeatability (7 cycles), excellent cross-selectivity, and relative humid resistance at 300 K. This research work provides insights on Cd ²⁺ incorporated Co₂SnO₄ thin films and their feasibility in real-time gas sensing devices.