First-Principles Studies of Hydrogen Adsorption at Pd-SiO2 Interfaces

The interaction of hydrogen with Pd-SiO2 interfaces has been investigated for the first time using first-principles calculations based on density functional theory. The hydrogen-induced polarization at the Pd-SiO2 interfaces was evaluated using Pd-SiO2 interface supercells. As a result, the potential change induced by interfacial hydrogen atoms was not observed even for hydrogen concentration of ~1.3 × 10(15) cm(-2) at the Pd-SiO2 interface. This result implies that hydrogen does not create an electric double layer at the Pd-SiO2 interface but change the property of the SiO2 region, resulting in the hydrogen sensitivity of the devices.