title: Flexible n-type thermoelectric materials by organic intercalation of layered transition metal dichalcogenide TiS2.
abstract: Organic semiconductors are attracting increasing interest as flexible thermoelectric materials owing to material abundance, easy processing and low thermal conductivity. Although progress in p-type polymers and composites has been reported, their n-type counterpart has fallen behind owing to difficulties in n-type doping of organic semiconductors. Here, we present an approach to synthesize n-type flexible thermoelectric materials through a facile electrochemical intercalation method, fabricating a hybrid superlattice of alternating inorganic TiS2 monolayers and organic cations. Electrons were externally injected into the inorganic layers and then stabilized by organic cations, providing n-type carriers for current and energy transport. An electrical conductivity of 790 S cm(-1) and a power factor of 0.45 mW m(-1) K(-2) were obtained for a hybrid superlattice of TiS2/[(hexylammonium)x(H2O)y(DMSO)z], with an in-plane lattice thermal conductivity of 0.12 ± 0.03 W m(-1) K(-1), which is two orders of magnitude smaller than the thermal conductivities of the single-layer and bulk TiS2. High power factor and low thermal conductivity contributed to a thermoelectric figure of merit, ZT, of 0.28 at 373 K, which might find application in wearable electronics.
authors: 1] Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan [2] State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors: Chunlei
authors: C
authors: Wan
authors: Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA.
authors: Xiaokun
authors: X
authors: Gu
authors: Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors: Feng
authors: F
authors: Dang
authors: Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors: Tomohiro
authors: T
authors: Itoh
authors: College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009, China.
authors: Yifeng
authors: Y
authors: Wang
authors: Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors: Hitoshi
authors: H
authors: Sasaki
authors: Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors: Mami
authors: M
authors: Kondo
authors: KOBELCO Research Institute, Kobe, Hyogo 651-2271, Japan.
authors: Kenji
authors: K
authors: Koga
authors: KOBELCO Research Institute, Kobe, Hyogo 651-2271, Japan.
authors: Kazuhisa
authors: K
authors: Yabuki
authors: Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
authors: G Jeffrey
authors: GJ
authors: Snyder
authors: Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA.
authors: Ronggui
authors: R
authors: Yang
authors: Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors: Kunihito
authors: K
authors: Koumoto