Perovskite oxides are ABO3‐type compounds with a crystal structure capable of accommodating a large number of elements at A‐ and B‐sites. Owing to their flexible structure and complex chemistry, they exhibit a wide range of functionalities as well as novel ground states at the interface. However, in comparison with conventional semiconductors such as silicon, they possess orders of magnitude lower room‐temperature electron mobilities limiting their room‐temperature electronic applications. For example, in a prototypical doped SrTiO3, the room‐temperature electron mobility remains below 10 cm2V−1s−1regardless of the defect minimization. Discovery of high room‐temperature mobility in alkaline‐earth stannates such as BaSnO3and SrSnO3constitutes a significant advancement toward all‐perovskite electronic and spintronic devices. Alkaline‐earth stannates also possess wide‐to‐ultra wide bandgaps that make them potentially suitable candidate for transparent conductors, power electronic devices, and high electron mobility transistors. This article provides an overview of the recent progress made to these materials' electrical properties with particular emphasis on the advancements in the molecular beam epitaxy approaches for their synthesis, and defect control.
Low-dimensional electronic state at the surface of a transparent conductive oxide
Abstract Materials that blend physical properties that are usually mutually exclusive could facilitate devices with novel functionalities. For example, the doped perovskite alkaline earth stannates BaSnO 3 and SrSnO 3 show the intriguing combination of high light transparency and high electrical conductivity. Understanding such emergent physics requires deep insight into the materials’ electronic structures. Moreover, the band structure at the surfaces of those materials can deviate significantly from their bulk counterparts, thereby unlocking novel physical phenomena. Employing angle-resolved photoemission spectroscopy and ab initio calculations, we reveal the existence of a 2-dimensional metallic state at the SnO 2 -terminated surface of 1% La-doped BaSnO 3 thin films. The observed surface state is characterized by a distinct carrier density and a lower effective mass compared to the bulk conduction band, of about 0.12 m e . These particular surface state properties place BaSnO 3 among the materials suitable for engineering highly conductive transition metal oxide heterostructures.
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- Award ID(s):
- 2011401
- NSF-PAR ID:
- 10411274
- Date Published:
- Journal Name:
- Communications Physics
- Volume:
- 5
- Issue:
- 1
- ISSN:
- 2399-3650
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1038/s42005-022-01091-y
