Semiconductor thermoradiative power conversion

Power can be generated from radiative exchange between two bodies with different temperatures—from the radiative cooling of the Earth’s surface into space, for example. Thermoradiative diodes are low-bandgap optoelectronic devices in which the occupancies of the valence and conduction bands are established through radiative exchange with the external environment. A warm diode viewing cold surroundings will spontaneously develop a reverse electrical bias, which, combined with the recombination current from the radiative imbalance, generates electrical power. Here we review the operating principles of the thermoradiative diode in both the radiative limit and in the presence of non-radiative processes. We discuss some present limitations and opportunities for improved performance together with potential applications such as night-sky power generation and waste-heat recovery. This article reviews the concept of using thermoradiative diodes for power conversion, and discusses potential applications such as night-sky power generation and waste-heat recovery.