Interfacial Thermal Conductance between Mechanically Exfoliated Black Phosphorus and SiOx: Effect of Thickness and Temperature

Black phosphorus (BP) is one of new 2D materials that have attracted wide attention. This work reports the interfacial thermal conductance between BP flake and SiOx using Raman spectroscopy. From 293 K down to the 223 K, eight BP flakes in a thickness range of 16.6–113.7 nm are characterized. At 293 K, the largest interfacial thermal conductance is 1.14 × 108 W m−2 K−1 for a 82.1 nm thick BP flake, and the smallest one is 2.17 × 107 W m−2 K−1 for a 26.6 nm thick BP flake. Such large interfacial thermal conductance can be attributed to the excellent interface contact and strong phonon coupling between BP and SiOx. The measured interfacial thermal conductance has a one‐fold up to around four‐fold increase with decreased temperature from 293 to 223 K, which is a result of thermal‐expansion‐mismatch induced variation in the morphology of BP flakes. Additionally, it demonstrates no thickness‐dependent behavior. It is speculated the intrinsic thickness dependence is weak and is overshadowed by the large variation in the interface contact of different samples. As a new 2D material, BP shows great potential to be a thermal interface material for heat dissipation in electronics. Interfacial thermal conductance between black phosphorus and SiOx is at the level of 20–600 MW m−2 K−1 in the temperature range between 223 and 293 K. It indicates an excellent interface contact between these two adjacent materials. It is observed that interfacial thermal conductance increases when temperature decreases. Besides, the interfacial thermal conductance shows little dependence on black phosphorus thickness. Thermal expansion mismatch between black phosphorus and Si substrate is responsible for the temperature‐dependence of interfacial thermal conductance.