Fabrication of Nanoscale Multilayered Thin Film-Based Integrated Thermoelectric Devices for Highly-Efficient Thermal-to-Electrical Energy Conversion and Solid-State Cooling in Naval Applications
Abstract
The research objective of this project is to use nanofabrication to develop highly-efficient integrated thermoelectric (TE) thin film power generators and cooling devices with an extremely high density of thermoelectric elements at nanoscale for high-efficiency thermal-to-electrical energy conversion and solid-state cooling in Naval applications. Thermoelectric power generators and thermoelectric refrigeration devices are extremely simple, and do not need any moving parts or bulk fluids for operation. These thermoelectric devices can have performance much superior to their vapor and gas-based counterparts, offering promising prospects of fully solid-state and environmentally benign energy conversion or cooling. However, the current use of thermoelectric devices is limited by their low efficiency. In this project, nanoscale multilayered thin films such as Bi2Te3/Sb2Te3, Bi2Te3/Bi2Te3-xSex, Si1-xGex/Ge, Si1-xGex/Bi2Te3, and Si1-xGex/Sb2Te3 will be used to fabricate the high-efficiency integrated power generators and cooling devices. Ultra-high-vacuum Ebeam/thermal evaporations will be used to grow the nanoscale multilayered thin films. The multilayered thin films will be prepared to have a periodic structure consisting of alternating layers, where each layer is about 1 to 5 nm thick, and have 150 to 300 layers with a total thickness of about 150 nm to 1500 nm. Integrated TE power generators and cooling devices will be fabricated with the multilayered thin films using the clean room-based nanofabrication techniques such as UV and e-beam lithography. The integrated TE devices will consist of thousands to millions of TE elements, where each TE element is fabricated with the multilayered thin film as the active layer, and has 20 to 1000 nm by 20 to 1000 nm in dimensions. The fabricated nanoscale multilayered supper lattice thin films and integrated TE devices will be further modified with the post-fabrication process such as innovative rapid cooling to enhance the nanolayer interface effect for achieving higher thermoelectric figure of merit. The fabrication of integrated TE devices with an extremely high density of TE elements will be specifically explored using the UV and e-beam lithography in this project. The dependence of efficiency on the density of TE elements at nanoscale will be investigated and found, and highly-efficient integrated TE devices will be developed and fabricated for high-efficiency thermal-to-electrical energy conversion and solid-state cooling in Naval applications. This project will greatly benefit ONR and contribute to the mission of ONR by providing highly -efficient integrated TE devices for thermoelectric power generation and solid-state cooling for Naval applications. Thermoelectric power sources have been widely used for Naval applications because of their capability for application in unusual situation and areas such as undersea, where conventional power sources can’t work well. The rising temperature limits device minimization and decreases its lifetime. Managing high heat flux is one of the most important technical challenges facing future Naval instrument electronics. Research on fabrication of TE devices for power generation and localized cooling has been intensive and extensive. However, the fabrication of highly-efficient integrated TE devices with an extremely high density of nanoscale TE elements is lacking and unexplored. This research will focus on the down-scaling of TE elements and exploring the dependence of thermal-to-electrical energy conversion and cooling efficiency on the density of TE elements at nanoscale, and highly-efficient integrated TE devices will be developed and fabricated. The project will also greatly enhance educational opportunities for majority underrepresented graduate and undergraduate students who will become tomorrow’s researchers in government, academia, and industries.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 07, 2017
- Source ID
- N000141712635
Entities
People
- Zhigang Xiao
Organizations
- Alabama A & M College
- Office of Naval Research
- United States Navy