The preparation and electrical conduction of Li/sub 2/SnO/sub 3/ thick film humidity sensitive material

摘要

Li/sub 2/SnO/sub 3/ thick film was fabricated as a humidity-sensitive material with high sensitivity, low temperature coefficient and humidity hysteresis, and long-time stability. The humidity sensitivity and electrical conduction under different values of relative humidity were investigated. The complex impedance spectrum of the materials was measured and a non-Debye model was introduced to study the conduction mechanism. The linear and inclined semi-circle complex impedance diagrams were observed in vacuum and environmental humidities, respectively. The equivalent parameters were calculated and related to the different regions in the materials, namely, grain, grain surface, and electrode surface. The results indicate that the main conduction carriers are H+ and Li+, and that the grain resistance is nearly independent of the relative humidity, whereas the resistance of the grain surface decreases with increasing relative humidity.