Graduate Student Researchers

Photon Enhanced Thermionic Emission (PETE) is a newly proposed form of solar energy harvesting which relies upon a combination of quantum and thermal processes to generate electricity. Unlike standard solar cells which rapidly lose efficiency at elevated temperatures, PETE is designed to operate at temperatures commensurate with thermal solar devices. In concentrated solar power designs the PETE module will receive the direct incident light, convert a fraction to electricity and transfer its waste heat to a solar thermal cycle. Theoretical efficiencies of combined PETE/solar thermal cycles reach above 50 % and may provide a route to affordable renewable energy on the utility scale. The key challenges to this technology are developing higher-efficiency cathodes that are stable at elevated temperatures, requiring both theoretical and experimental analysis of new materials. In the past months, theoretical work has established efficiency limits and determined several key materials properties and geometries to optimize PETE efficiency. We have constructed a new surface preparation and characterization chamber designed specially for PETE that can provide detailed measurements of material performance under anticipated operating conditions. Preliminary measurements have shown promising steps towards increasing efficiency