This Faculty Early Career Development (CAREER) Program grant provides funding to investigate new processing mechanisms of nanostructuring bulk nitrides and oxides with multiple length-scale structures for high temperature thermoelectric power generation. The underlying hypothesis is that multiple length-scale nanostructures can be controlled by process engineering and thus be used as an effective method to tune thermoelectric properties by decoupling electrical and thermal properties. To test this hypothesis, an integrated experimental and theoretical study is used to examine the processing-related parameters including atomic-scale, nanoscale, and micro-scale structures and their corresponding effects on thermoelectric properties. Gallium nitride and zinc oxide are the model systems for this work due to their promising thermoelectric properties and mechanical and chemical stability at high temperatures.
If successful, this program will enable a new class of cost-effective, thermally stable and nontoxic thermoelectric materials for wasted energy recovery at high temperatures. A total of 1500 trillion BTU/year of waste heat is generated from industrial processes where temperatures typically exceed 1000K. A new class of thermoelectric materials that are robust up to 1000K will make a key contribution to recover this wasted energy since the operational temperature of current technology is limited to below 800K. The science gained from this project can be transformed more broadly into the further development of thermoelectric, photovoltaic, and laser devices. The educational contributions of this CAREER project include creating interdisciplinary education and research modules within energy-related curriculums, enhancing underrepresented students' participation in science and engineering, and outreach to K-12 students to pursue a career in science and engineering.
