Bandgap Controlling of Oxygen-Vacancy-Induced Two-Dimensional Electron Gas in SrTiO3

Strongly correlated oxides are full of fascinating phenomena owing to their interacting lattice, charge, spin and orbital degrees of freedom. Here we report a large bandgap enhancement in SrTiO3 thin films due to their defective nature, which was found to significantly change the electronic and magnetic phases in the oxygen-vacancy-induced two-dimensional electron gas at the interface between amorphous LaAlO3 and SrTiO3. Density functional theory calculations show the possibility of the role of Sr/Ti antisite defects on the observed properties. This may open an attractive path to tailor electronic, magnetic and optical properties of SrTiO3-based oxide interface systems under intense focus in the oxide electronics community.