Creation and control of quasi-two dimensional electron gas at yttrium aluminum oxides/strontium titanate heterointerfaces by spin coating

Despite of extensive researches about oxide heterointerfaces, preparing method and intrinsic mechanism are all challenging topics. Here, we generate a series of stable quasi two dimensional electron gases (q-2DEGs) at yttrium aluminum oxides/strontium titanate (YAO/STO) heterointerfaces by the spin coating for the first time. It is found that the thickness and the stoichiometry ratio are the key factors for the creation of q-2DEG, which is formed under the premise of thickness (about 81.1 ∼ 356.4 nm) and the rich-Al (Al:Y≥1:1). The underlying mechanism can be attributed to oxygen vacancies derived from the redox reaction between YAO film and STO substrate. In addition, the conductive behavior can be modulated by the light illumination and the value of photoinduced change reaches 153.7% at low temperature. This work paves a novel way to fabricate 2DEG massively and helpful for a deep understanding about the conductive mechanism of oxide heterostructures.