Improvement of Sensing Performance of Impedancemetric C₂H₂ Sensor Using SmFeO₃ Thin-Films Prepared by a Polymer Precursor Method.

A sensitive an impedancemetric acetylene (C₂H₂) gas sensor device could be fabricated by using perovskite-type SmFeO₃ thin-film as a sensor material. The uniform SmFeO₃ thin-films were prepared by spin-coating and focusing on the effects of polymer precursor solutions. The prepared precursors and thin-films were characterized by means of thermal analysis, Fourier-transform infrared spectroscopy, ultraviolet⁻visible spectroscopy, X-ray diffraction analysis, scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that particle growth and increase in homogeneity of the prepared thin-film could be accelerated by the addition of acetyl acetone (AcAc) as a coordination agent in the polymer precursor solution. Moreover, the highly crystallized thin-film-based sensor showed good response properties and stabilities to a low C₂H₂ concentration between 0.5 and 2.0 ppm.