Bandgap Control of the Oxygen-Vacancy-Induced Two-Dimensional Electron Gas in SrTiO
نویسندگان
چکیده
greater than the bulk value, depending on the deposition temperature. There is no signifi cant change in density and cationic ratio of the oxide so the effect is attributed to Sr/Ti antisite defects, an attribution supported by density functional theory calculations. It was found that the bandgap enhancement signifi cantly changes the electronic and magnetic phases in the oxygen-vacancy-induced two-dimensional electron gas at the interface between amorphous LaAlO 3 (LAO) and STO. This opens an attractive path to tailor electronic, magnetic and optical properties of STO-based oxide interface systems under intensive focus in the oxide electronics community. Meanwhile, our study provides key insight into the origin of the fundamental issue that STO thin fi lms are diffi cult to convert into metals by oxygen vacancy doping. STO is central to modern oxide electronics since it serves as the main workhorse for complex functional oxide heterostructure fabrications. After the two-dimensional electron gas (2DEG) at the interface between STO and LAO had been unveiled, [ 7 ] a large number of exotic properties of the 2DEG were revealed such as a critical thickness for the appearance of conductivity, [ 8 ] Kondo effect, [ 9 ] interface superconductivity, [ 10 ]
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