Enhancing the electron mobility via delta-doping in SrTiO3

TL;DR

This study demonstrates that delta-doping in SrTiO3 thin films can significantly enhance electron mobility at low temperatures by confining high-mobility electrons in clean undoped regions, providing a platform for 2D electron gas research.

Contribution

The paper introduces a novel delta-doping technique in SrTiO3 that increases electron mobility by confining electrons in undoped regions, with detailed analysis of the transport properties.

Findings

Mobility exceeds bulk values in thinner doped layers

High-mobility electrons are located in undoped regions

Structure is ideal for studying 2D electron gases in SrTiO3

Abstract

We fabricated high-mobility {\delta}-doped structures in SrTiO3 thin films in order to investigate the low temperature electronic transport properties of confined carriers in this system. An enhancement of the electron mobility above the bulk value was observed as the doped layer thickness decreased. High-field Hall measurements revealed that this mobility enhancement originates from higher-mobility electrons in the undoped clean regions, which have quantum-mechanically broadened from the doped layer. Because of the absence of apparent lattice misfit between the layers, this structure is highly suitable for investigating two-dimensional electron gases in SrTiO3.