%A Rongqian Wang, Jincheng Lu, and Jian-Hua Jiang %T Moderate-Temperature Near-Field Thermophotovoltaic Systems with Thin-Film InSb Cells %0 Journal Article %D 2021 %J Chin. Phys. Lett. %R 10.1088/0256-307X/38/2/024201 %P 024201%V 38 %N 2 %U {https://cpl.iphy.ac.cn/CN/abstract/article_105833.shtml} %8 2021-01-04 %X 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 sandwiched 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 $1.3\times10^{5}$ W/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.