High sensitivity resistive hydrogen sensor using palladium–vanadium bilayer composite thin film structure

Improving the sensitivity of palladium thin film resistive hydrogen sensors to detect trace amounts of hydrogen is critical for hydrogen leakage warning and transformer condition monitoring. However, the solid solution scattering effect makes it challenging to enhance the sensitivity of the sensors through commonly used material modification methods such as elemental doping. To address this issue, this study proposes a method to improve the sensitivity of resistive hydrogen sensors using palladium-vanadium bilayer composite thin film structure. The research results show that, compared to the pure Pd film resistive hydrogen sensor, the resistive hydrogen sensor fabricated with the Pd–V bilayer composite film exhibited an increase in sensitivity, as the relative resistance change increased by a factor of 22 to hydrogen at a trace concentration of 15 ppm and the linear sensitivity of the sensor increased by a factor of 1.87 within a hydrogen concentration range of 15–1000 ppm.