Impedance-based interfacial analysis of the LaAlO3/SrTiO3 oxide heterostructure involving a 2-dimensional electron gas layer

• Published in: The Journal of physics and chemistry of solids Vol. 82; pp. 60 - 66
• Main 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
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2015
• Subjects: 2DEG; Impedance spectroscopy; Interface; LaAlO3/SrTiO3; Oxygen vacancies; LaAlO3/SrTiO3; Oxygen vacancies; 2DEG; Impedance spectroscopy; Interface
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2015.03.002

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. •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.