Surface state at $BaSn{O}_3$ evidenced by angle-resolved photoemission spectroscopy and ab initio calculations

Abstract

Perovskite alkaline earth stannates, such as $BaSn{O}_3$ and $SrSn{O}_3$, showing light transparency and high electrical conductivity (when doped), have become promising candidates for novel optoelectrical devices. Such devices are mostly based on hetero-structures and understanding of their electronic structure, which usually deviates from the bulk, is mandatory for exploring a full application potential. Employing angle-resolved photoemission spectroscopy and ab initio calculations we reveal the existence of a 2-dimensional metallic state at the $Sn{O}_2$-terminated surface of a 1\% La-doped $BaSn{O}_3$ thin film. The observed surface state is characterized by distinct carrier density and a smaller effective mass in comparison with the corresponding bulk values. The small surface effective mass of about $0.12m_e$ can cause an improvement of the electrical conductivity of BSO based heterostructures.

References in corpus (7)

• Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface
• Unveiling a two-dimensional electron gas with universal subbands at the surface of SrTiO3
• High Mobility in a Stable Transparent Perovskite Oxide
• Mixed Dimensionality of Confined Conducting Electrons in the Surface Region of SrTiO${}_3$
• First-principles analysis of electron transport in BaSnO${}_3$
• Electron effective mass and mobility limits in degenerate perovskite stannate BaSnO${}_3$
• 2DEGs at perovskite interfaces between KTaO3 or KNbO3 and stannates