We investigated the electronic reconstruction at the n-type LaAlO 3/SrTiO 3 interface with hard x-ray photoelectron spectroscopy (HAXPES) under grazing incidence. By exploiting the collapse of evanescent x-ray waves and the abrupt increase of x-ray absorption at the critical incidence angle, our HAXPES study reveals a 2% electronic reconstruction from Ti 4+ to Ti 3+ occurring near the interface. Such an electronic reconstruction also extends from the interface into SrTiO 3 with a depth of about 48Å (∼12 unit cells) and an estimated total charge transfer of ∼0.24 electrons per two-dimensional unit cell.
|Number of pages||3|
|Journal||Applied Physics Letters|
|State||Published - 26 Dec 2011|