2021/01/26 by Wang, Rongqian, Lu, Jincheng, Jiang, Jian-Hua
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2101.10604
Near-field thermophotovoltaic systems functioning at 400∼900~K based on graphene-hexagonal-boron-nitride heterostructures and thin-film InSb p-n junctions are investigated theoretically. The performances of two near-field systems with different emitters are examined carefully. One near-field system consists of a graphene-hexagonal-boron-nitride-graphene sandwich structure as the emitter, while the other system has an emitter made of the double graphene-hexagonal-boron-nitride heterostructure. It is shown that both systems exhibit higher output power density and energy efficiency than the near-field system based on mono graphene-hexagonal-boron-nitride heterostructure. The optimal output power density of the former device can reach to 1.3×105~\rmW⋅ m-2, while the optimal energy efficiency can be as large as 42% of the Carnot efficiency. We analyze the underlying physical mechanisms that lead to the excellent performances of the proposed near-field thermophotovoltaic systems. Our results are valuable toward high-performance moderate temperature thermophotovoltaic systems as appealing thermal-to-electric energy conversion (waste heat harvesting) devices.