Screen printed Zn-doped nanostructured In2O3 thick films, characterizations, and enhanced NO2 gas sensing at low temperature

The pristine and various mole% (1, 3, 5, 7, and 9) Zn-doped In2O3 nanocrystalline materials have been successfully prepared via the facile sol-gel and screen-printing thick film methods. The crystalline and morphological information for the samples were investigated using various techniques such as XRD, FESEM, HR-TEM, EDAX analysis, and AFM. All the fabricated sensor devices were employed to investigate sensing properties. The resistivity and activation energy properties of all samples were investigated. The 7 % mole Zn doped In2O3 sensor showed superior gas sensing properties and showed excellent selectivity towards NO2 gas than other doped and pure In2O3 sensors. The sensors were tested at different operating temperatures for NO2 gas. The highest response of 117 was revealed for 100 ppm NO2 gas at 50 °C temperature. The optimal sensor device was tested for different NO2 gas concentrations (50–500 ppm) and long-term stability (90 days). The plausible sensing mechanism was briefed. The Zn doped In2O3 materials could be a potential candidate for highly selective, low-temperature commercial NO2 sensor device production.