Enhancing the CO2 sensor response of nickel oxide-doped tin dioxide thin films synthesized by SILAR method

The present article investigates the chemiresistive gas sensing characteristics of undoped and nickel oxide-doped tin oxide gas sensors at different concentrations synthesized by a SILAR technique. The structural analysis revealed a tetragonal crystal structure with (110) dominant diffraction peaks and crystallite sizes ranging between 26 and 32 nm. When the NiO dopant concentration was increased to 7% by volume, AFM analysis revealed the development of island-like stairs on the surface of the SnO2 film, with the average grain size rising from 28.16 to 36.12 nm. FESEM micrographs revealed a porous surface with nano-spherical structures clustered together to form a sea stone-like structure with particle sizes ranging from 23.8 to 42.3 nm. When exposed to CO2, the developed sensor exhibits a rapid response time and strong stability properties. At an operating temperature of 323 K, the 5 percent nickel oxide-doped sample displayed the maximum sensor response (128%), with a response time of 13 s and a recovery time of 34 s. The designed sensor's dynamic response improved as the CO2 concentration increased. According to the sensing results, the 5% nickel oxide-doped film exhibits stability in the ambient atmosphere.

Automated summary

The chemiresistive gas sensing characteristics of undoped and nickel oxide-doped tin oxide gas sensors at different concentrations synthesized by a SILAR technique were investigated. The results showed that the nickel oxide dopant improved the crystal structure and grain size. The developed sensor exhibited rapid response and strong stability to CO2, with the response increasing as the concentration increased.