Tuning Interfacial Thermal Transport through Phase Engineering in 2D Ferroelectrics.

As a 2D material with distinctive ferroelectric properties, InSe offers significant potential for the applications in information memory and advanced data storage technologies. It also exhibits a complex phase diagram that is highly sensitive to temperature and pressure variations, resulting in diverse lattice configurations. While extensive studies have focused on the phase transition behavior of InSe, its impact on phonon transport remains largely unexplored. In this work, the interfacial thermal transport in mechanically exfoliated few-layer α-InSe is probed for the first time. Using Raman spectroscopy and electrical property measurements, a significant shift is observed in both the Raman peaks and electrical characteristics ≈ 65 K, where the electrical resistance changes by two orders of magnitude. Furthermore, by using the 3ω method, notable variations are detected in the interfacial thermal resistance near 65 K, indicating a phase transition induced by lattice distortion at low temperatures. In contrast, no comparable changes appeared ≈ 500 K, suggesting that high-temperature phase transitions induce subtler impacts on thermal transport. The ability to modulate the interfacial thermal resistance through phase transitions in 2D ferroelectrics InSe presents a promising approach to addressing the thermal management challenges of next-generation data storage technologies.