Analysis of heterostructures for electroluminescent refrigeration and light emitting without heat generation

We perform a self-consistent calculation to investigate the feasibility of electroluminescent refrigeration and light emitting without heat generation in AlGaAs/GaAs heterostructures, taking into account the effects of various recombination processes. The effect of radiation extraction on the cooling capacity and efficiency is also considered. Carrier blocking layers are used to almost eliminate current leakage and improve the injection efficiency to nearly 100%. An analysis is presented of the cooling power density, the cooling efficiency, and the radiative power density as functions of the applied voltage. We also explore the dependences of the cooling related quantities on the thickness and the doping of the active region. A GaAs active layer of thickness 5 mu m at 300 K can give a limiting cooling power density of 97 W/cm(2). We show that a net cooling power (>several W/cm(2)) and a high-power light emitting (>100 W/cm(2)) without heating are feasible. They require an overall efficiency of more than 90%, which is easily achieved if the photon recycling efficiency is high. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3326944]