Premium
Enhancing the Thermoelectric Device Performance of Graphene Using Isotopes and Isotopic Heterojunctions
Author(s) -
Anno Yuki,
Takei Kuniharu,
Akita Seiji,
Arie Takayuki
Publication year - 2015
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.201500175
Subject(s) - graphene , materials science , thermoelectric effect , heterojunction , seebeck coefficient , thermoelectric materials , chemical vapor deposition , semiconductor , carbon fibers , optoelectronics , thermal conductivity , nanotechnology , analytical chemistry (journal) , composite material , thermodynamics , chemistry , physics , composite number , chromatography
The thermoelectric properties of various graphene samples, including isotopically modified heterostructures grown by chemical vapor deposition, are investigated from the viewpoint of thermoelectric device applications. The thermoelectric power of graphene varies from −80 to 90 μV K −1 , depending on the applied gate voltage. Similar to typical metals and semiconductors, the thermoelectric power of graphene decreases as the electrical conductivity increases, regardless if isotopes are present. The results follow a line with a slope of −198 μV K −1 in the Jonker plot, indicating that the maximum power factor is 5.29 × 10 −3 W m −1 K −2 irrespective of carbon isotope modulation in graphene. Because limiting phonon propagation independent of the electric properties can reduce the thermal conductivity of graphene containing carbon isotopes and isotopic heterojunctions, introducing carbon isotopes into the graphene structure improves the thermoelectric figure of merit without affecting the power factor.