Role of Native Defect in Near Room Temperature CH4 Sensing Using Nanostructured V2O5

Native defects are highly prevalent in vanadium pentoxide (V2O5) as it can easily get converted into reduced oxides. The role of defects in gas sensing properties of V2O5 nanostructures, however, are not well understood. In the present report, effect of native defects on near room temperature sensing is reported for the first time. Hydrothermally grown V2O5 nanoparticles with substantial sensor response to CH4 close to room temperature at 50 °C is presented. Fast response and recovery times of 43 s and 75 s, respectively, for 500 ppm CH4 gas at optimum operating temperature of 150 °C were observed. Temperature dependent photoluminescence studies were carried out to understand the role of native defects and their emission behavior leading to carrier saturation in realizing optimum operating temperature.