Effect of Dimensionality and Pd-Doping on the Microstructure of SnO2DPublic Deposited
The need for high-performance, solid-state H2 gas sensors is one research effort aimed at enabling the future hydrogen economy. Improving the gas-sensing properties of semiconducting oxide materials such as tin oxide, zinc oxide, etc., necessitates the control microstructure and composition. This study compares the effect of dimensionality with the effect of Pd-doping on the grain size of tin (IV) oxide. If tin oxide is fabricated as a line instead of a thin film, it is expected that the average grain size can be significantly reduced, independent of Pd-doping effects. Thin-film and line samples of Pd-doped and undoped tin oxide were fabricated using a sol-gel method and soft-electron beam lithography. X-ray photoelectron spectroscopy (XPS) was used to quantify the composition of the deposited tin oxide, and transmission electron microscopy (TEM) was used to image the tin oxide grain morphology. The effect of dimensionality was found to reduce the average tin oxide grain size by about 40% compared with a thin film. On the other hand, 3% doping of Pd reduced the grain size by as much as 30%, even in a thin film. Comparison of doped and undoped lines did not show a difference in the grain size, possibly because the effect is not cumulative. This research supports the potential of hydrogen gas sensors made from Pd-doped tin oxide lines, which could have enhanced gas-sensing performance due to their reduced grain size.