Hydrogen gas sensing properties of Pd/a-C:Pd/SiO2/Si structure at room temperature

Hydrogen gas (H2) sensor based on palladium/palladium doped amorphous carbon film/SiO2/Si (Pd/a-C:Pd/SiO2/Si) structure is fabricated. It is found that H2 molecules have dramatic effect on the current–voltage (I–V) characteristic of the novel Pd/a-C:Pd/SiO2/Si structure at room temperature. Upon exposure to 1.6% H2 at a reverse bias voltage of −0.5 V, the currents of the Pd/a-C:Pd/SiO2/p-Si and Pd/a-C:Pd/SiO2/n-Si structures change about 840% and 13,100%, respectively. The results show that the Pd/a-C:Pd/SiO2/Si structure has high H2 response. The sensing mechanism of the Pd/a-C:Pd/SiO2/Si structure has also been discussed.