Enhanced LPG sensing characteristics of Pt doped SnO2 based thick film resistors

High yield synthesis of nanocrystalline SnO2 was carried out using two step thermal decomposition route. The structural and optical characterization of powder was done using XRD, SEM and UV-Vis spectroscopy. Synthesized SnO2 along with 15 wt% of glass frit was used as a functional material to fabricate thick film resistors using screen printing technology. Platinum layers of various thicknesses (20–100 nm) were deposited on the surface of samples by sputter coating technique. The samples were tested for 300 ppm concentration of LPG. The sensors doped with 80 nm thickness of Pt exhibits enhanced response of (∼3×10³) which is 10 times higher than un-doped sensors with low operating temperature (140°C), fast response (10s) and recovery time (20s). These sensors were found to be extremely stable and repeatable with a minimum detection limit of 5 ppm of LPG.