Abstract
Thermoelectric multilayer thin films used in nanoscale energy conversion have been receiving increasing attention in both academic research and industrial applications. Thermal transport across multilayer interface plays a key role in improving thermoelectric conversion efficiency. In this study, the cross-plane thermal conductivities of nano-constructed Sb2Te3/(Cu, Ag, Au, Pt) thermoelectric multilayer thin films have been measured using time-domain thermoreflectance method. The interface morphology features of multilayer thin film samples were characterized by using scanning and transmission electron microscopes. The effects of interface microstructure on the cross-plane thermal conductivities of the multilayer thin films have been extensively examined and the thermal transfer mechanism has been explored. The results indicated that electron–phonon coupling occurred at the semiconductor/metal interface that strongly affected the cross-plane thermal conductivity. By appropriately optimizing the period thickness of the metal layer, the cross-plane thermal conductivity can be effectively reduced, thereby improving the thermoelectric conversion efficiency. This work presents both experimental and theoretical understanding of the thermal transport properties of Sb2Te3/metal multilayer thin film junctions with important implications for exploring a novel approach to improving the thermoelectric conversion efficiency.
Highlights
With the ever increasing of energy demanded, to develop sustainable energy sources strategy becomes more and more concerned in recent years, Thermoelectric technology, harvesting electric power from heat, is a promising environmentally friendly means of energy conversion
In order to investigate the effects of metal layer on traditional P-Type thermoelectric materials, Sb2Te3/X (X = Cu, Ag, Au, Pt) thermoelectric multilayer thin film with various period thickness were prepared using the magnetron sputtering method
The experimental results indicated that nanometer multilayer interface microstructures have a significant effect on the cross-plane thermal conductivity
Summary
With the ever increasing of energy demanded, to develop sustainable energy sources strategy becomes more and more concerned in recent years, Thermoelectric technology, harvesting electric power from heat, is a promising environmentally friendly means of energy conversion. The thermoelectric technology has an inherent advantage to harvest widely distributed waste heat, and proved as an alternative route to convert solar energy into electric power economically [1]. The thermoelectric energy conversion efficiency is determined by the dimensionless figure of merit ZT, where Z is a measure of a material’s thermoelectric properties and T is absolute temperature. S, electrical conductivity σ and thermal conductivity κ, yielding equation Z = S2·σ/κ. To maximize the ZT value of thermoelectric device, a large Seebeck coefficient, high electrical conductivity, and low thermal conductivity are most expected [3, 4]. In order to improve the thermoelectric efficiency, various approaches to enhancing ZT have been proposed and developed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
