Effects of charge rearrangement on interfacial contact resistance of TiO2/graphite from first-principles calculations

The results show that the Schottky barrier depends on the charge distribution induced by graphite. When the charge depletion and accumulation layer are mainly distributed in the space-charge region, the contact resistance is determined by the conductivity of the doped TiO2. For example, the n-type Schottky barrier is formed between graphite and the n-type of Sb-doped TiO2. In the contrast, if the charge rearrangement occurs in the heterojunction as a whole, the contact resistance relies on the electronic injection of graphite. For instance, the n-type Schottky barrier is formed between graphite and the p-type of Ge-doped TiO2. We hope that the formation mechanisms and the control strategies of the contact resistance between titanium oxides and graphite can be used to develop new materials with a high conductivity.