Metallic behavior in STO/LAO heterostructures with non-uniformly atomic interfaces

Abstract

The search for new and low-power switching devices involving the integration of semiconductor thin films is of interest, and has led to renewed research because such devices may exhibit innovative properties. Here, we investigate the two-dimensional electron gas (2DEG) at the LaAlO3/SrTiO3 interface with metallic and insulator behavior. Insight is offered by quantifying the interface charge distribution associated with structural and electronic order-disorder effects. Variations in the electron conductivity were observed to be associated with different specific clustering arrangements of both Ti and Al cations of the co-exposed surfaces at the interface, i.e., structural and electronic connectivity among the undercoordinated [TiO5] and [AlO5] clusters. These results indicate facet control as a strategy for enhancing the electric and magnetic properties of a device via the quantum confinement of electrons.