Near-field radiative heat transfer between black phosphorus and graphene sheet

Low thermal conductivity of black phosphorus (BP) makes it difficult to cool BP-based electronic or optoelectronic devices. Therefore, developing a cooling strategy for BP-based nano devices is highly required. We theoretically study the near-field radiative heat transfer between BP sheets as well as between BP and graphene. We find that the heat transfer between BP sheets is determined by its electron doping. Plasmons excited by BP in different directions dominate the heat transfer for different electron doping. At optimum electron doping, heat transfer between the BP sheets increases significantly. The heat transfer between BP and graphene is dependent on both the electron doping of BP and chemical potential of graphene. Modulating the chemical potential of graphene can result in a strong coupling between graphene plasmons and BP plasmons, which will lead to a significant enhancement of heat transfer between BP and graphene. Our results are not only meaningful in controlling the heat transfer between BP-based structures but also helpful in developing cooling strategies for BP-based nano devices.