Enhanced, selective, and room temperature detection of ethanol vapor by RF-sputtered TiO2 thin films

In this research study, TiO2 thin films-based ethanol sensors were fabricated by RF magnetron sputtering technique. The devices' structure, surface morphology, and sensing performance were engineered by changing the sputtering power. The characteristics of sensing materials were studied by grazing incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM), and field emission scanning electron Microscopy (FESEM). The produced samples at low powers (100 and 200 W) had a tetragonal structure with a mixed phase of anatase and rutile whereas the sample deposited at the power of 300 W represented a single phase of anatase. The results showed that the variation of sputtering power had a significant effect on the ethanol vapor sensing performance of the devices due to the change in crystallographic structure, phase, and surface morphology. The sample produced at the sputtering power of 200 W showed more sensitivity than the other samples. The mentioned device also showed enhanced sensitivity compared to the previous reports due to its dual structure.