Carrier density control of the surface 2DEG on SrTiO3(001)
Our study of the origin of the two-dimensional electron gas (2DEG) stabilized at the bare surface of SrTiO3 (001) has been accepted for publication in Advanced Materials.
Using high-resolution angle resolved photoemission and core level spectroscopy we investigated the origin of the two-dimensional electron gas (2DEG) stabilized at the bare surface of SrTiO3 (001). We show conclusively that this 2DEG arises from light-induced oxygen vacancies and identify the dominant mechanism driving the formation of vacancies. This study opens a new route to tune the carrier density in oxide 2DEGs with great potential for fast spatial patterning. Moreover, it allows us unprecedented control over the 2DEG carrier density, which we use to unravel systematic variations in the electronic structure that provide strong support for an interpretation in terms of quantum confinement.