Sensing properties controlled by thickness variable of palladium oxide synthesized by RF-reactive sputtering

Palladium oxide (PdO) thin films were deposited by RF reactive magnetron sputtering onto glass substrates. The argon and oxygen partial pressures were (9.43 × 10−3 Torr) and (1.87 × 10−2 Torr) at room temperature respectively. The thicknesses of the deposited films were in the range of about (50-150 nm). Necessary thickness, structural, electrical and sensing properties of PdO films were methodically examined. X-ray diffraction method has shown a polycrystalline structure with a preferred reflection peak at (220) plane. The scanning electron microscope analysis has revealed a growth of nanoparticles in all prepared films. Electrical properties have shown strong dependence on thickness variation. Gas sensitivity of nitrogen dioxide and hydrogen gases were about (91%) and (90%) respectively. It was observed that gas sensitivity of PdO thin films increases as the film thickness increases.