2DEGs at perovskite interfaces between KTaO3 or KNbO3 and stannates

TL;DR

This study uses density functional theory to explore electron-rich interfaces between perovskite oxides and stannates, revealing how interfacial electron gases form and can be manipulated by ferroelectricity, with implications for electronic control.

Contribution

It provides detailed computational analysis of electron gas formation at perovskite-stannate interfaces and highlights the potential for electrical control via ferroelectricity.

Findings

Interfacial electron gases can form on either side of the interface.

Ferroelectricity can shift the electron gases away from the interface.

Interfaces exhibit diverse behaviors depending on conditions.

Abstract

We report density functional studies of electron rich interfaces between KTaO3 or KNbO3 and CaSnO3 or ZnSnO3 and in particular the nature of the interfacial electron gasses that can be formed. We find that depending on the details these may occur on either the transition metal or stannate sides of the interface and in the later case can be shifted away from the interface by ferroelectricity. We also present calculations for bulk KNbO3, KTaO3, CaSnO3, BaSnO3 and ZnSnO3, showing the different transport and optical properties that may be expected on the two sides of such interfaces. The results suggest that these interfaces may display a wide range of behaviors depending on conditions, and in particular the interplay with ferroelectricity suggests that electrical control of these properties may be possible.