Controlling the electronic interface properties of AlO$_x$/SrTiO$_3$ heterostructures

Abstract

Depositing disordered Al on top of SrTiO3 is a cheap and easy way to create a two-dimensional electron system in the SrTiO3 surface layers. To facilitate future device applications we passivate the heterostructure by a disordered LaAlO3 capping layer to study the electronic properties by complementary x-ray photoemission spectroscopy and transport measurements on the very same samples. We also tune the electronic interface properties by adjusting the oxygen pressure during film growth.