Near-field radiative transfer based thermal rectification using doped silicon

In this letter, we have designed a near-field thermal rectifier using a film and a bulk of doped silicon, with different doping levels, separated by a vacuum gap. We examine the origin of nonlinearities in thermal rectification associated with near-field heat transfer, and investigate closely the effects of varying the vacuum gap and the film thickness on rectification. For a 10 nm thick film, rectification greater than 0.5 is achieved for vacuum gaps varying from 1 nm to 50 nm with the hot and cold temperatures of the terminals of the rectifier being 400 K and 300 K, respectively. The results obtained from this study may benefit future research in thermal management and energy harvesting.