Near-field electroluminescent cooling with wide-bandgap semiconductors

Electroluminescent cooling involves a forward-biased light-emitting diode with electroluminescence exceeding the input electricity, leading to refrigeration of the diode. Achieving electroluminescent cooling with significant cooling power requires near-unity luminescent efficiency. While diodes based on wide-bandgap semiconductors have shown the highest wall plug efficiency, therefore holding great potential for electroluminescent cooling, electroluminescent cooling with wide-bandgap semiconductors remains largely unexplored. Existing studies of electroluminescent cooling have been focused on using semiconductors with a relatively small bandgap. Here, we study electroluminescent cooling of wide-bandgap diodes using the framework of fluctuational electrodynamics. We investigate cooling power and coefficient of performance for electroluminescent cooling using blue and green indium gallium nitride diodes. Our calculation shows that near-field energy transfer can greatly enhance both cooling power and coefficient of performance. We show that electroluminescent cooling with a blue indium gallium nitride diode can provide cooling power as high as 106W/m2, at 250 K, and with a coefficient of performance of 0.017. Moreover, it can operate to cryogenic temperature as low as 50 K. Our findings highlight the opportunity of high power, cryogenic solid-state cooling by using wide-bandgap semiconductors.