Incompatibility of Pure SnO₂ Thin Films for Room-Temperature Gas Sensing Application

Abstract

Despite the high sensitivity and selectivity, the high operating temperature required for activation energy of tin oxide (SnO 2 ) still stands as a drawback for SnO 2 based gas sensors. In this work, the SnO 2 thin films were deposited through spray pyrolysis and were subjected to gas sensing at 27 °C (room temperature) towards different gases. The films exhibited a consistently low response of approximately 1 when tested to various VOCs. The type, concentration, and mobility of charge carriers were determined from the Hall measurements. The high carrier concentration accompanied by poor mobility and grain boundary scattering is supposed to hinder its performance at room temperature. The obtained film had spherical morphology, which lead to grain boundary scatterings and decreased the mobility of carriers.

Preparation of Antimony Tin Oxide Thin Film Using Green Synthesized Nanoparticles by E-Beam Technique for NO2 Gas Sensing

“…The resistance variation of ATO thin films concerning temperature is shown in Figure 6. The film resistance was measured in steps of 50 • C at temperatures ranging from 150 • C to 350 • C. The characteristics show that the film resistance significantly decreases as the temperature rises, confirming the semiconductor behavior of ATO films [30][31][32][33][34]. At different temperatures, due to the increased surface conductivity of the annealed films, the resistance is lesser than as-deposited films.…”