Reducing dependence on fossil fuels is a major challenge. In addition, there is direct correlation between energy use and economic development. Whether the focus is on reducing the depletion of natural resources, expanding the diversity of energy production, reduction in climate change, or achieving greater energy security, there is a growing need to use energy in a smarter manner, as well as generating energy from renewable sources. To this end, thermoelectricity, a solid-state scheme directly converting heat into electricity, can play a key role. Thermoelectric devices are especially attractive since they have no moving parts, are very reliable, ecologically clean, and allow for a wide range of industrial to consumer applications. A crucial aspect for commercial applications are materials with desired transport properties to maximize the efficiency of energy production. This project uses a synergistic approach, with computational, experimental, and device development aspects, to investigate a new class of materials with applications in thermoelectricity. These low-cost material systems have earth-abundant constituents that can be synthesized in high yields, which is especially attractive from both environmental and commercial perspectives. A fundamental understanding of these new materials is also important, and allows for rapid and effective development strategies for enhanced thermoelectric performance benefiting industrial development of clean, low cost thermoelectric power conversion devices.
TECHNICAL DETAILS: In this project, a new class of multinary chalcogenides composed of earth-abundant constituents as thermoelectric materials is being explored. Thermodynamic phase stability calculations, electronic and phonon structure properties, and the governing transport mechanisms are being investigated using first principles simulations. Models for structure-property relations are being used for alloying and defect engineering in the laboratory in order to obtain compositions with optimized thermoelectric properties. Experimental synthesis and characterization serve as validation in addition to input towards further iterations with an eye to improving computational and theoretical models. Additional experimental capabilities and device development are provided by the partnership with Marlow Industries, Inc., a world leader in thermoelectric devices and applications. This collaborative project provides an excellent platform for graduate student engagement in the research, and outreach activities for high school students in the local urban and surrounding rural areas.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
