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

TL;DR

This study investigates how depositing Al and LaAlO$_3$ layers on SrTiO$_3$ affects the electronic interface properties, using spectroscopy and transport measurements to explore tunability for device applications.

Contribution

It demonstrates a method to control SrTiO$_3$ interface properties via Al deposition, LaAlO$_3$ passivation, and oxygen pressure adjustments, providing insights for electronic device engineering.

Findings

Passivation with LaAlO$_3$ stabilizes electronic properties.

Oxygen pressure during growth tunes interface conductivity.

Complementary spectroscopy and transport measurements validate control methods.

Abstract

Depositing disordered Al on top of SrTiO$_3$ is a cheap and easy way to create a two-dimensional electron system in the SrTiO$_3$ surface layers. To facilitate future device applications we passivate the heterostructure by a disordered LaAlO$_3$ 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.