Moderate-temperature near-field thermophotovoltaic systems with thin-film InSb cells

TL;DR

This paper theoretically investigates near-field thermophotovoltaic systems with thin-film InSb cells operating at 400-900K, demonstrating enhanced power density and efficiency using graphene-based heterostructure emitters.

Contribution

It introduces and compares two novel near-field TPV systems with graphene-hexagonal-boron-nitride heterostructure emitters, achieving higher performance than previous designs.

Findings

Optimal power density of 1.3×10^5 W/m^2 achieved

Energy efficiency up to 42% of Carnot limit

Both systems outperform mono graphene-hexagonal-boron-nitride emitter systems

Abstract

Near-field thermophotovoltaic systems functioning at 400$\sim$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 $1.3\times10^{5}~\rm{W\cdot m^{-2}}$, 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.