Growth mode control of the free carrier density in SrTiO3-d films

TL;DR

This study investigates how to control the growth mode and electronic properties of SrTiO3-d films during pulsed laser deposition, enabling systematic doping and high-mobility metallic films through tuning surface kinetics.

Contribution

It introduces a method to control growth mode and doping in SrTiO3-d films by tuning surface crystallization and oxidation kinetics during deposition.

Findings

Persistent 2D layer-by-layer growth achieved for hundreds of unit cells.

Controlled oxygen vacancies enable systematic doping across a metal-insulator transition.

High Hall mobility of up to 25,000 cm2/Vs in metallic films.

Abstract

We have studied the growth dynamics and electronic properties of SrTiO3-d homoepitaxial films by pulsed laser deposition. We find the two dominant factors determining the growth mode are the kinetics of surface crystallization and oxidation. When matched, persistent two-dimensional layer-by-layer growth can be obtained for hundreds of unit cells. By tuning these kinetic factors, oxygen vacancies can be frozen in the film, allowing controlled, systematic doping across a metal-insulator transition. Metallic films can be grown, exhibiting Hall mobilities as high as 25,000 cm2/Vs.