title: Thermoelectrics. Dense dislocation arrays embedded in grain boundaries for high-performance bulk thermoelectrics.
abstract: The widespread use of thermoelectric technology is constrained by a relatively low conversion efficiency of the bulk alloys, which is evaluated in terms of a dimensionless figure of merit (zT). The zT of bulk alloys can be improved by reducing lattice thermal conductivity through grain boundary and point-defect scattering, which target low- and high-frequency phonons. Dense dislocation arrays formed at low-energy grain boundaries by liquid-phase compaction in Bi(0.5)Sb(1.5)Te3 (bismuth antimony telluride) effectively scatter midfrequency phonons, leading to a substantially lower lattice thermal conductivity. Full-spectrum phonon scattering with minimal charge-carrier scattering dramatically improved the zT to 1.86 ± 0.15 at 320 kelvin (K). Further, a thermoelectric cooler confirmed the performance with a maximum temperature difference of 81 K, which is much higher than current commercial Peltier cooling devices.
authors.affiliation: Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, South Korea. sang.il.kim@samsung.com kimsungwng@skku.edu.
authors.forename: Sang Il
authors.initials: SI
authors.lastname: Kim
authors.affiliation: Department of Nano Applied Engineering, Kangwon National University, Chuncheon 200-701, South Korea.
authors.forename: Kyu Hyoung
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Energy Science, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746, South Korea. IBS Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon 440-746, South Korea.
authors.forename: Hyeon A
authors.initials: HA
authors.lastname: Mun
authors.affiliation: Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, South Korea. Materials Science, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Hyun Sik
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Hwang
authors.affiliation: Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Jong Wook
authors.initials: JW
authors.lastname: Roh
authors.affiliation: Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Dae Jin
authors.initials: DJ
authors.lastname: Yang
authors.affiliation: Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Weon Ho
authors.initials: WH
authors.lastname: Shin
authors.affiliation: Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Xiang Shu
authors.initials: XS
authors.lastname: Li
authors.affiliation: Department of Energy Science, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746, South Korea. IBS Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon 440-746, South Korea.
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Energy Science, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746, South Korea. Materials Science, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: G Jeffrey
authors.initials: GJ
authors.lastname: Snyder
authors.affiliation: Department of Energy Science, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746, South Korea. IBS Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon 440-746, South Korea. sang.il.kim@samsung.com kimsungwng@skku.edu.
authors.forename: Sung Wng
authors.initials: SW
authors.lastname: Kim