▎ 摘　　要

Graphene-hexagonal-boron-nitride-InSb near-field structures are designed and optimized to enhance the output power and energy efficiency of the thermophotovoltaic systems working in the temperature range of common industrial waste heat, from 400 to 800 K, which is also the working temperature range for conventional thermoelectric devices. We show that the highest output electric power can reach 7.6 x 10(4) W/m(2) for the system with a graphene-hexagonal-boron-nitride heterostructure as the emitter and a graphene-covered InSb p-n junction as the absorber, while the highest energy efficiency is achieved by the system with the heterostructure as the emitter and an uncovered InSb p-n junction as the absorber (reaching to 34% of the Carrot efficiency). These results show that the performances of near-field thermophotovoltaic systems can be comparable with or even superior to state-of-the-art thermoelectric devices. The underlying physics for the significant enhancement of the thermophotovoltaic performance is understood as due to the resonant coupling between the emitter and the p-n junction, where the surface plasmons in graphene and surface-phonon polaritons in boron nitride play crucial roles. Our study provides a stepping stone toward future high-performance thermophotovoltaic systems.