Large Enhancement of 2D Electron Gases Mobility Induced by Interfacial Localized Electron Screening Effect

Large Enhancement of 2D Electron Gases Mobility Induced by Interfacial Localized Electron Screening Effect

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 30(2018), 22 vom: 12. Mai, Seite e1707428
1. Verfasser: Chi, Xiao (VerfasserIn)
Weitere Verfasser: Huang, Zhen, Asmara, Teguh C, Han, Kun, Yin, Xinmao, Yu, Xiaojiang, Diao, Caozheng, Yang, Ming, Schmidt, Daniel, Yang, Ping, Trevisanutto, Paolo E, Whitcher, T J, Venkatesan, T, Breese, Mark B H, Ariando, Rusydi, Andrivo
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2018
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article 2D electron gases X-ray and optical spectra highly interfacial electron mobility oxide heterostructures screening effect
Beschreibung
Zusammenfassung:© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The interactions between delocalized and localized charges play important roles in correlated electron systems. Here, using a combination of transport measurements, spectroscopic ellipsometry (SE), and X-ray absorption spectroscopy (XAS) supported by theoretical calculations, we reveal the important role of interfacial localized charges and their screening effects in determining the mobility of (La0.3 Sr0.7 )(Al0.65 Ta0.35 )O3 /SrTiO3 (LSAT/SrTiO3 ) interfaces. When the LSAT layer thickness reaches the critical value of 5 uc, the insulating interface abruptly becomes conducting, accompanied by the appearance of a new midgap state. This midgap state emerges at ≈1 eV below the Ti t2g band and shows a strong character of Ti 3dxy - O 2p hybridization. Increasing the LSAT layer from 5 to 18 uc, the number of localized charges increases, resulting in an enhanced screening effect and higher mobile electron mobility. This observation contradicts the traditional semiconductor interface where the localized charges always suppress the carrier mobility. These results demonstrate a new strategy to probe localized charges and mobile electrons in correlated electronic systems and highlight the important role of screening effects from localized charges in improving the mobile electron mobility at complex oxide interfaces
Beschreibung:Date Completed 06.08.2018
Date Revised 01.10.2020
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.201707428