Direct visualization and control of SrOx segregation on semiconducting Nb doped SrTiO3 (100) surface

TL;DR

This study visualizes and controls SrOx segregation on Nb doped SrTiO3 surfaces, revealing how morphology and electronic properties can be manipulated for potential electronic device applications.

Contribution

It introduces a method to directly visualize and control SrOx segregation patterns and electronic properties on SrTiO3 surfaces.

Findings

SrOx forms labyrinth domain patterns during annealing

Surface miscut angle influences domain pattern formation

Segregated SrOx exhibits lower work function than SrTiO3

Abstract

We investigated how SrOx segregates on a Nb doped SrTiO3 (100) surface by in air annealing. Using atomic force and photoemission electron microscopes, we can directly visualize the morphology and the electronic phase changes with SrOx segregation. SrOx islands less than 2 micron meter in size and 1-5 unit cells thick nucleate first and grow in a labyrinth domain pattern. After prolonged annealing, SrOx forms a ~10 nm thick film. We show that the domain pattern can be controlled by introducing a surface miscut angle of SrTiO3. Additionally, the segregated SrOx has a lower work function, compared to that of SrTiO3. These results suggest that the control and tunability of SrOx segregation is applicable to the design of a new functional electronic devices in the semiconducting SrTiO3 based heterostructure.