Origin of the Superior Conductivity of Perovskite Ba(Sr)SnO3

TL;DR

This paper explains the high electron conductivity of Ba(Sr)SnO3 perovskites through first-principles calculations, highlighting their small effective masses and doping potential, which make them promising transparent conductors.

Contribution

It provides a detailed first-principles analysis of the electronic structure of Ba(Sr)SnO3, revealing the origin of their high conductivity and doping capabilities.

Findings

Small electron effective masses due to large Sn size

Easy doping with La creating shallow donor levels

Potential as transparent conducting oxides

Abstract

ASnO3 (A=Ba, Sr) are unique perovskite oxides in that they have superior electron conductivity despite their wide optical band gaps. Using first-principles band structure calculations, we show that the small electron effective masses, thus, good electron conductivity of ASnO3 can be attributed to the large size of Sn in this system that gives the conduction band edge with antibonding Sn and O s characters. Moreover, we show that ASnO3 can be easily doped by La with shallow LaA(+/0) donor level. Our results, therefore, explained why the perovskite BaSnO3, SrSnO3, and their alloys are promising candidates for transparent conducting oxides.