TY - JOUR
T1 - Cross-plane thermoelectric Seebeck coefficients in nanoscale Al 2 O 3 /ZnO superlattice films
AU - Yoon, Yo Seop
AU - Lee, Won Yong
AU - Park, No Won
AU - Kim, Gil Sung
AU - Ramos, Rafael
AU - Takashi, Kikkawa
AU - Saitoh, Eiji
AU - Koo, Sang Mo
AU - Park, Jin Seong
AU - Lee, Sang Kwon
N1 - Funding Information:
This study was supported by the Priority Research Centers Program and the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology (2016R1A2B2012909 and 2017R1D1A1B03031010). This study was supported through Technology Transfer Center for National R & D Program by the Ministry of Science & ICT (2018K000282).
PY - 2019
Y1 - 2019
N2 - Superlattice thin films, which are used in thermoelectric (TE) devices for small-scale solid-state cooling and for generating electrical power, have recently been attracting attention due to their low dimensionality, low thermal conductivity, and enhanced power factor. Considering the measurement techniques for characterizing TE properties, very limited information, including cross-plane Seebeck coefficients of superlattice films, has been reported. This information is required for the assessment of the interface between the films and to understand phonon scattering in superlattice films. In this report, thermally stable cross-plane thermoelectric Seebeck coefficients of Al 2 O 3 /ZnO (AO/ZnO) superlattice films are presented, at temperature differences (ΔT) ranging from 2 to 12 K. Longitudinal (in-plane) thermal diffusion in the Cu/AO/ZnO/Cu samples, which occurred during the measurements due to the size differences among the samples located between a micro-Peltier and aluminum nitride cooling plate, was investigated. The cross-plane Seebeck coefficients of 3- and 6-cycled AO/ZnO superlattice films were determined to be ∼9.4 ± 0.4 and ∼30.6 ± 0.7 μV K −1 , respectively, showing stable values in the evaluated ΔT range. Two distinct phenomena, in-plane thermal diffusion and the effect of the environment, were identified in cross-plane Seebeck measurements as dominant factors controlling the temperature coefficient of AO/ZnO superlattice films. In addition, a new TE parameter, the Seebeck temperature coefficient, was proposed for superlattice films.
AB - Superlattice thin films, which are used in thermoelectric (TE) devices for small-scale solid-state cooling and for generating electrical power, have recently been attracting attention due to their low dimensionality, low thermal conductivity, and enhanced power factor. Considering the measurement techniques for characterizing TE properties, very limited information, including cross-plane Seebeck coefficients of superlattice films, has been reported. This information is required for the assessment of the interface between the films and to understand phonon scattering in superlattice films. In this report, thermally stable cross-plane thermoelectric Seebeck coefficients of Al 2 O 3 /ZnO (AO/ZnO) superlattice films are presented, at temperature differences (ΔT) ranging from 2 to 12 K. Longitudinal (in-plane) thermal diffusion in the Cu/AO/ZnO/Cu samples, which occurred during the measurements due to the size differences among the samples located between a micro-Peltier and aluminum nitride cooling plate, was investigated. The cross-plane Seebeck coefficients of 3- and 6-cycled AO/ZnO superlattice films were determined to be ∼9.4 ± 0.4 and ∼30.6 ± 0.7 μV K −1 , respectively, showing stable values in the evaluated ΔT range. Two distinct phenomena, in-plane thermal diffusion and the effect of the environment, were identified in cross-plane Seebeck measurements as dominant factors controlling the temperature coefficient of AO/ZnO superlattice films. In addition, a new TE parameter, the Seebeck temperature coefficient, was proposed for superlattice films.
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U2 - 10.1039/c8tc05114c
DO - 10.1039/c8tc05114c
M3 - Article
AN - SCOPUS:85061267417
VL - 7
SP - 1670
EP - 1680
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
SN - 2050-7526
IS - 6
ER -