Hydrogen interaction with Pd/SiO2/Si rectifying junction

The interaction between hydrogen and Pd/SiO2/Si structures has been investigated in this research. Palladium (Pd) films <2 nm thick which are consisted of Pd nanoparticles were deposited on n-type Si and sapphire substrates by magnetron sputtering. We have observed that the surface resistance of Pd/SiO2/Si structure increased more than 20 times within 1.4 s at room temperature during the hydrogen exposure. Our comparison results between the surface I–V characteristic of Pd/SiO2/Si and Pd/Al2O3 indicate that the reduction in the carrier density of the interfacial layer is the major contribution to the surface resistance change in Pd/SiO2/Si. Further comparison results between the surface I–V characteristic of Pd/SiO2/Si and Pd/Si reveal that the interfacial layer is the inversion layer (p-type) of the rectifying junction.