Electrophoretic deposition of SnO2 nanoparticles in non-aqueous medium for sensor applications

Nanosized SnO₂ based sensors are widely used for gas sensing applications because of their low operating temperature and high surface area. SnO₂ films are conventionally deposited by chemical vapor deposition, evaporation, sol-gel and sputtering which are very expensive, time consuming processes and complex. In contrast, electrophoretic deposition (EPD) is simple, cost effective which makes it possible to fabricate reliable porous coatings. The aim of this work is to deposit porous and homogenous SnO₂ films by using EPD and to investigate the surface morphology of the films for gas sensor production. In this study nanosized SnO₂ (60nm) particles were used in non-aqueous mediums with and without iodine to prepare stabilized EPD suspension. Homogeneous and porous film layers were processed and analyzed at various time and voltages. The results showed that highly porous, crack free and homogeneous SnO₂ films on Pt coated alumina substrate were achieved for 5 and 15 seconds at 100V EPD parameters. Optimum sintering between the SnO₂ nanoparticles was observed at 500^oC. Deposited film thickness of 5 μm was measured by scanning electron microscopy. According to initial results, EPD deposited SnO₂ films showed high sensitivity to liquified petroleum gas (LPG) at various gas concentration and operation temperature.