Electrical power generation from moderate-temperature radiative thermal sources.

Moderate-temperature thermal sources (100-400°C) that radiate waste heat are often the by-product of mechanical work, chemical or nuclear reactions, or information processing. We demonstrate conversion of thermal radiation into electrical power using a bipolar grating-coupled complimentary metal-oxide-silicon (CMOS) tunnel diode. A two-step photon-assisted tunneling charge pumping mechanism results in separation of charge carriers in pn junction wells leading to a large open-circuit voltage developed across a load. Electrical power generation from a broadband blackbody thermal source has been experimentally demonstrated with converted power densities of 27-61 μW/cm2 for thermal sources between 250-400°C. Scalable, efficient conversion of radiated waste heat into electrical power can be utilized to reduce energy consumption, or to power electronics and sensors.