This Faculty Early Career Development (CAREER) award looks to develop new approaches to the use of nanocrystals in the formation of thermoelectric materials and devices. Flexible thermoelectric and electronic films have the potential to impact a broad range of applications in energy harvesting, cooling and flexible electronics. The conventional thermoelectric and electronic devices are rigid, and fabricated using complex and relative costly processes. Additive manufacturing or printing-based approaches offer low-cost and highly scalable means to assemble colloidal nanocrystals of unique properties into flexible thermoelectric and electronic devices. Nanocrystals of thermoelectric materials, because of their small size, can be formed into inks which can be printed onto flexible substrates and in useful near-final-form structures. The thermal and electrical properties of the nanocrystals and their mutual interfaces need to be understood and controlled in working devices. The interfacial chemistry and the response of the nanocrystal-based film's thermoelectric behavior under processing conditions is critical to achieving the highest performance thermoelectric materials. These nanocrystal-based processes and materials could open new application areas impacting US manufacturing and opening new application area beyond thermoelectrics. The integrated research and education program provides educational opportunities to broad range of audiences, including the development of educational kits in thermoelectrics development and institutional and outreach programs to enhance interest from K-12 students, teachers and members of underrepresented groups in STEM careers through participation in NSF REU/RET, LSAMP, e-Girls, and e-Camp, to support workforce development in the manufacturing and advanced materials areas to address increasing needs in the sustainable energy and electronic technologies.
This research aims to achieve bulk-like charge carrier mobility and an over two-fold increase in thermoelectric figure of merit ZT compared with current state-of-the-art flexible films. The research will address a pressing need to convert the nanocrystals into a useful form within a scalable and low-cost manufacturing process. The project will complete four objectives to establish a new paradigm for processing colloidal nanocrystals from nanoscale-to-macroscale: (1) synthesis of nanocrystals, and control their size, surface chemistry and doping, (2) print and sinter flexible films, with controlled interfacial chemistry, (3) establish the processing-structure-property relationship, and (4) design and print proof-of-concept devices. The research outcomes will not only significantly advance the manufacturing processes for flexible thermoelectric and electronic materials, but also generate new knowledge in the formation and use of functional nanocrystalline materials within an additive printing platform.
