Radiant refrigeration by semiconductor diodes

Abstract

Dousmanis et al. [Phys. Rev. 133, A316 (1964)] demonstrated that GaAs light-emitting diodes could produce a cooling effect if the quantum efficiency (ratio of photon flux to junction current) is very close to unity (e.g., >0.97). Here, it is pointed out that for narrow-bandgap semiconductors, the quantum efficiency need not be so high to produce cooling. Also, for narrow-bandgap semiconductors there is an additional cooling mode in which the reverse-biased diode cools its radiant environment by absorbing infrared radiation. Maximum cooling rates per unit of junction area are on the order of n2σT4, where n is the index of refraction, σ is the Stefan–Boltzmann constant, and T is the temperature. For small cooling rates the efficiency for cooling can approach the limit imposed by the second law of thermodynamics.