title: Free-electron creation at the 60° twin boundary in Bi2Te3.
abstract: Interfaces, such as grain boundaries in a solid material, are excellent regions to explore novel properties that emerge as the result of local symmetry-breaking. For instance, at the interface of a layered-chalcogenide material, the potential reconfiguration of the atoms at the boundaries can lead to a significant modification of the electronic properties because of their complex atomic bonding structure. Here, we report the experimental observation of an electron source at 60° twin boundaries in Bi2Te3, a representative layered-chalcogenide material. First-principles calculations reveal that the modification of the interatomic distance at the 60° twin boundary to accommodate structural misfits can alter the electronic structure of Bi2Te3. The change in the electronic structure generates occupied states within the original bandgap in a favourable condition to create carriers and enlarges the density-of-states near the conduction band minimum. The present work provides insight into the various transport behaviours of thermoelectrics and topological insulators.
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Kwang-Chon
authors.initials: KC
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan.
authors.forename: Joohwi
authors.initials: J
authors.lastname: Lee
authors.affiliation: High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Byung Kyu
authors.initials: BK
authors.lastname: Kim
authors.affiliation: KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701, Republic of Korea.|Center for Spintronics, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Won Young
authors.initials: WY
authors.lastname: Choi
authors.affiliation: Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|Department of Nanomaterials, Korea University of Science and Technology, Daejeon 305-333, Republic of Korea.
authors.forename: Hye Jung
authors.initials: HJ
authors.lastname: Chang
authors.affiliation: Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Sung Ok
authors.initials: SO
authors.lastname: Won
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Beomjin
authors.initials: B
authors.lastname: Kwon
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Seong Keun
authors.identifier: 0000-0001-8712-7167
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Dow-Bin
authors.initials: DB
authors.lastname: Hyun
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Hyun Jae
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701, Republic of Korea.|Center for Spintronics, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Hyun Cheol
authors.initials: HC
authors.lastname: Koo
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Jung-Hae
authors.initials: JH
authors.lastname: Choi
authors.affiliation: High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Dong-Ik
authors.initials: DI
authors.lastname: Kim
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Jin-Sang
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|Department of Nanomaterials, Korea University of Science and Technology, Daejeon 305-333, Republic of Korea.
authors.forename: Seung-Hyub
authors.initials: SH
authors.lastname: Baek