Light-Emitting Diodes for Solid-State Refrigeration

Electroluminescence, the conversion of electrons into externally emitted photons, is an intrinsic cooling process in a light-emitting diode as long as the applied voltage is less than the photon energy. When the diode is sufficiently efficient so that cooling due to electroluminescence surpasses heating due to internal losses, it becomes a solid-state refrigerator. We present the theoretical performance limits of a solid-state refrigerator that combines an optimized GaAs light-emitting diode and a GaAs photovoltaic cell. We show that at moderate power densities, this optoelectronic refrigerator can outperform thermoelectric coolers in cooling efficiency and is also a viable technology for cryogenic cooling applications.