Year: 2009
Type: article
Abstract: Metal/semiconductor superlattices have the potential for a high thermoelectric figure of merit. The thermopower of these structures can be enhanced by controlling the barrier height using high-energy electron filtering. In addition, phonon scattering at interfaces can reduce the lattice contribution to the thermal conductivity. In this paper, we present theoretical and experimental studies of the thermoelectric transport in ZrN/ScN metal/semiconductor superlattices. Preliminary measurement results show an exponential increase in the cross-plane electrical conductivity with increasing temperature, which indicates the presence of the barrier. Fit of the Boltzmann transport-based model with the data indicates a barrier height of 280 meV. The cross-plane Seebeck coefficient of the sample is also measured by combining Seebeck voltage transient measurements with the thermal imaging technique. A Seebeck coefficient of 820 μ V/K at room temperature is extracted, which is in good agreement with the simulation result of 800 μ V/K. Theoretical calculations predict that the ZrN/ScN structure can exhibit a ZT of 1.5 at 1300 K assuming lateral momentum is conserved and that a ZT of 3 is achievable if the lateral momentum is not conserved.
Source: Journal of Electronic Materials
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,390
OpenAlex ID: W2095192024