First-principles simulations on bulk Ta₂O₅ and Cu/Ta₂O₅ /Pt heterojunction: Electronic structures and transport properties

Electronic structures and transport properties of bulk Ta₂O ₅ and Cu/Ta₂O₅ /Pt heterojunction have been studied from first principles. Of the two room-temperature phases of bulk Ta₂O₅, Β -, and δ - Ta₂O ₅, our calculated results showed that the Β phase has much narrower band gap than the δ - Ta₂O₅. For Cu/δ - Ta₂O₅ /Pt heterojunction, the p -type Schottky barriers between the Cu (Pt) and Ta₂O₅ were estimated as 0.9-1.2 eV. Both the standard density-functional calculation and the nonequilibrium Green's function showed that no conducting channels were formed from Cu to Pt through δ - Ta₂O₅.