Integrated Near-Field Thermophotovoltaic Device Overcoming Blackbody Limit

Abstract

Near-field thermal radiation transfer overcoming the blackbody limit has attracted significant attention in recent years owing to its potential for drastically increasing the output power and conversion efficiency of thermophotovoltaic (TPV) power generation systems. Here, we experimentally demonstrate a one-chip near-field TPV device overcoming the blackbody limit, which integrates a 20-μm-thick Si emitter and an InGaAs PV cell with a subwavelength gap (<140 nm). The device exhibits a photocurrent density of 1.49 A/cm² at 1192 K, which is 1.5 times larger than the far-field limit at the same temperature. In addition, we obtain an output power of 1.92 mW and a system efficiency of 0.7% for a 1 mm² device, both of which are 1 to 2 orders of magnitude greater than those of the previously reported near-field systems. Detailed comparisons between the simulations and experiments reveal the possibility of a system efficiency of >35% in the up-scaled device, thus demonstrating the potential of our integrated near-field TPV device for practical use in the future.