Impedance-based interfacial analysis of the LaAlO3/SrTiO3 oxide heterostructure involving a 2-dimensional electron gas layer. (July 2015)

• Record Type: Journal Article
• Authors: Park, Chan-Rok; Ik Kim, Shin; Young Moon, Seon; You, Yil-Hwan; Hwan Seo, Jung; Baek, Seung-Hyub; Keun Kim, Seong; Kang, Chong-Yun; Kim, Jin-Sang; Hwang, Jin-Ha
• Is Part Of: Journal of physics and chemistry of solids. Volume 82(2015:Jul.)
• Page Start: 60
• Page End: 66
• Publication Date: 2015-07
• Subjects: Impedance spectroscopy -- 2DEG -- Interface -- LaAlO3/SrTiO3 -- Oxygen vacancies; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2015.03.002
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: The 2-dimensional electron gas (2DEG) at the LaAlO3 /SrTiO3 heterointerface was analyzed using frequency-dependent impedance spectroscopy. The electrical conduction of 2DEG significantly influences the high-frequency impedance and induces dielectric amplification at low frequency regimes. The impedance responses obtained from the LaAlO3 /SrTiO3 oxide was modeled using an equivalent circuit model. The frequency-dependent characterization used here does not necessitate the formation of ohmic contacts between the 2DEG layer and the adjacent electrodes. Through thermal bias-stress tests, the 2DEG conduction mechanism is proposed to partially originate from the oxygen vacancy-controlled defect concepts, indicating the controllability of 2DEG transport. Highlights: 2-dimensional electron gas (2DEG) is formed at LaAlO3 /SrTiO3 heterointerface. Impedance spectroscopy was applied onto the 2DEG LaAlO3 /SrTiO3 system. The 2DEG LaAlO3 /SrTiO3 system was modeled using an equivalent circuit model. The origin of the 2EDG layer was interpreted in terms of oxygen vacancy defects.