title: Electric-field-induced shift in the threshold voltage in LaAlO3/SrTiO3 heterostructures.
abstract: The two-dimensional electron gas (2DEG) at the interface between insulating LaAlO3 and SrTiO3 is intriguing both as a fundamental science topic and for possible applications in electronics or sensors. For example, because the electrical conductance of the 2DEG at the LaAlO3/SrTiO3 interface can be tuned by applying an electric field, new electronic devices utilizing the 2DEG at the LaAlO3/SrTiO3 interface could be possible. For the implementation of field-effect devices utilizing the 2DEG, determining the on/off switching voltage for the devices and ensuring their stability are essential. However, the factors influencing the threshold voltage have not been extensively investigated. Here, we report the voltage-induced shift of the threshold voltage of Pt/LaAlO3/SrTiO3 heterostructures. A large negative voltage induces an irreversible positive shift in the threshold voltage. In fact, after the application of such a large negative voltage, the original threshold voltage cannot be recovered even by application of a large positive electric field. This irreversibility is attributed to the generation of deep traps near the LaAlO3/SrTiO3 interface under the negative voltage. This finding could contribute to the implementation of nanoelectronic devices using the 2DEG at the LaAlO3/SrTiO3 interface.
authors.affiliation: 1] Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea [2] Department of Nanomaterials Science and Technology, Korea University of Science and Technology, Daejeon, 305-333, Republic of Korea.
authors.forename: Seong Keun
authors.initials: SK
authors.lastname: Kim
authors.affiliation: 1] Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea [2] Department of Nanomaterials Science and Technology, Korea University of Science and Technology, Daejeon, 305-333, Republic of Korea.
authors.forename: Shin-Ik
authors.initials: SI
authors.lastname: Kim
authors.affiliation: 1] Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea [2] Department of Materials Science and Engineering, Seoul National University, Seoul, 151-744, South Korea.
authors.forename: Hyungkwang
authors.initials: H
authors.lastname: Lim
authors.affiliation: 1] Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea [2] Department of Nanomaterials Science and Technology, Korea University of Science and Technology, Daejeon, 305-333, Republic of Korea.
authors.forename: Doo Seok
authors.initials: DS
authors.lastname: Jeong
authors.affiliation: Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea.
authors.forename: Beomjin
authors.initials: B
authors.lastname: Kwon
authors.affiliation: 1] Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea [2] Department of Nanomaterials Science and Technology, Korea University of Science and Technology, Daejeon, 305-333, Republic of Korea.
authors.forename: Seung-Hyub
authors.initials: SH
authors.lastname: Baek
authors.affiliation: Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea.
authors.forename: Jin-Sang
authors.initials: JS
authors.lastname: Kim