Electrical properties of Pd-oxide-InP structures

Pd-anodic oxide-InP metal-oxide-semiconductor (MOS) structures are fabricated to develop a hydrogen sensor capable of effectively operating at room temperature. The conduction mechanisms of the structures at 100–300 K are studied. It is found that the oxide behaves as ohmic resistance and the rectifying properties of the structures are determined by the potential barrier at the oxide-InP interface with the thermal-tunneling charge transport mechanism. The structures greatly change their characteristics in the presence of hydrogen in the ambient medium.