Cross-Plane Seebeck Coefficient Measurement of Misfit Layered Compounds (SnSe)n(TiSe2)n(n = 1,3,4,5).
We report cross-plane thermoelectric measurements of misfit layered compounds (SnSe)n(TiSe2)n(n = 1,3,4,5), approximately 50 nm thick. Metal resistance thermometers are fabricated on the top and bottom of the (SnSe)n(TiSe2)nmaterial to measure the temperature difference and heat transport through the material directly. By varying the number of layers in a supercell, n, we vary the interface density while maintaining a constant global stoichiometry. The Seebeck coefficient measured across the (SnSe)n(TiSe2)nsamples was found to depend strongly on the number of layers in the supercell (n). When n decreases from 5 to 1, the cross-plane Seebeck coefficient decreases from -31 to -2.5 μV/K, while the cross-plane effective thermal conductivity decreases by a factor of 2, due to increased interfacial phonon scattering. The cross-plane Seebeck coefficients of the (SnSe)n(TiSe2)nare very different from the in-plane Seebeck coefficients, which are higher in magnitude and less sensitive to the number of layers in a supercell, n. We believe this difference is due to the different carrier types in the n-SnSe and p-TiSe2layers and the effect of tunneling on the cross-plane transport.
Zhen
0000-0003-0886-2994
Z
Li
Department of Chemistry, University of Oregon , Eugene, Oregon 97403-1253, United States.
Sage R
SR
Bauers
Nirakar
N
Poudel
Department of Chemistry, University of Oregon , Eugene, Oregon 97403-1253, United States.
Danielle
0000-0002-9262-1060
D
Hamann
Department of Physics and Astronomy University of Toledo , Toledo, Ohio 43606-3390, United States.|Institute for Advanced Materials, Devices and Nanotechnology, Rutgers University , Piscataway, New Jersey 08854, United States.
Xiaoming
X
Wang
Department of Mechanical Engineering, The University of Texas at Austin , Austin, Texas 78712-0292, United States.
David S
DS
Choi
Department of Mechanical and Aerospace Engineering, University of Virginia , Charlottesville, Virginia 22904-4746, United States.
Keivan
K
Esfarjani
Department of Mechanical Engineering, The University of Texas at Austin , Austin, Texas 78712-0292, United States.
Li
L
Shi
Department of Chemistry, University of Oregon , Eugene, Oregon 97403-1253, United States.
David C
DC
Johnson
Stephen B
SB
Cronin
2D material stack; Intergrowth compounds; Seebeck coefficient; cross-plane