In 2009, the Solid-State Solar-Thermal Energy Conversion (S3TEC) Center began to pursue its mission: to create novel solid-state materials and devices that can convert sunlight and heat into electricity—efficiently, at low cost, and with no moving parts. S3TEC was established as an Energy Frontier Research Center by the US Department of Energy, with funding of $17.5 million over five years. It is directed by Gang Chen, MIT’s Carl Richard Soderberg Professor of Power Engineering and director of the Pappalardo Micro and Nano Engineering Laboratories. The work involves a diverse group of experts at MIT, Boston College, Oak Ridge National Laboratory, and Rensselaer Polytechnic Institute. At MIT, participants include 11 faculty members from five departments in the Schools of Engineering and Science.
Key to the research are two solid-state technologies that can convert heat from the sun and other sources into electricity. “Solar thermoelectric energy conversion” uses solar radiation to create a temperature difference across a solid-state material, which then generates electricity. In “solar thermophotovoltaic” devices, solar radiation first raises the temperature of an object; that object then emits photons optimized to the bandgap of a photovoltaic cell, and the cell generates electricity. Both technologies can also operate on heat from other sources, including geothermal heat and waste heat from industrial processes, transportation, and buildings.
The S3TEC researchers have already achieved fundamental advances that are, for example, enabling them to fabricate thermoelectric devices with significantly increased efficiency and to create spectrally selective surfaces critical to high-performance thermophotovoltaic systems.