Investigation on near-field radiative heat transfer between two SiC films with different substrates

Abstract

Near-field radiative heat transfer (NFRHT) has drawn significant attention in the past years due to potential applications in energy harvesting, and information storage. In practical applications, the substrate is necessary to make the structure more stable. However, the investigation of substrate influence on the NFRHT in previous works is rarely carried out. In this work, the influence of the substrate on the NFRHT between two SiC films is investigated. For lossless substrates, the NFRHT is enhanced in thick films (h = 7 nm and h = 20 nm), while suppressed in thin films (h = 1 nm). For lossy substrates, the loss of the substrate can effectively promote the NFRHT. The substrates of real materials are also considered. We find the NFRHT between two SiC films is suppressed, when the substrates are Au and SiO2. The underlying physics mechanism can be explained by the antisymmetric and symmetric mode of surface phonon polaritons (SPhPs) in SiC films, which are analyzed by the energy transmission coefficients (ETCs) as a function of angular frequency and wavevector. In addition, we find that the dispersion relations and ETCs exhibit a good agreement. We believe this work is helpful in understanding the effect of substrates on SPhPs and designing near-field radiation devices.