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.

电力可以通过两个不同温度的物体之间的辐射交换产生，例如，从地球表面到太空的辐射冷却。热辐射二极管是低带隙光电器件，其中价带和导带的占据是通过与外部环境的辐射交换建立的。一个温暖的二极管观察寒冷的环境会自发地产生反向电偏压，它与辐射不平衡产生的复合电流相结合，产生电能。在这里，我们回顾了热辐射二极管在辐射极限和非辐射过程存在下的工作原理。我们讨论了提高性能的一些现有限制和机会，以及夜间发电和余热回收等潜在应用。