Evaluation of IDE-based flexible thin film ZnO sensor for VOC sensing in a custom designed gas chamber at room temperature

We report the fabrication of Interdigitated Electrode-based thin film Zinc oxide sensor to study volatile organic compounds (VOCs) like 1-butanol, ethanol, acetone, xylene and toluene. The VOC sensing studies were carried out at 50 ppm level and results showed the highest relative response of 28.6% towards 1-butanol at RT (27 °C). Surface characterization of the ZnO structure using XRD, FESEM, EDAX and AFM is discussed which showed uniform hexagonal disc-like structure of ZnO, in hexagonal wurtzite phase of highly crystalline nature. UV–visible spectra showed a maximum absorbance at 360 nm and band gap energy of 3.03 eV (Tauc’s plot). ZnO sensor showed good sensitivity for 1-butanol VOC and hence the sensor is tested towards 1-butanol in a custom designed, portable gas chamber with cost-effective instrumentation circuit. It is observed that the sensing results in gas chamber closely matched with that obtained through Keithley instrument. A cost-effective, portable, VOC sensing system can be realized.