Molecular dynamics study of interfacial thermal transport between silicene and substrates

Abstract

In this work, the interfacial thermal transport across silicene and various substrates, i.e., crystalline silicon (c-Si), amorphous silicon (a-Si), crystalline silica (c-SiO2) and amorphous silica (a-SiO2) are explored by classical molecular dynamics (MD) simulations. A transient pulsed heating technique is applied in this work to characterize the interfacial thermal resistance in all hybrid systems. It is reported that the interfacial thermal resistances between silicene and all substrates decrease nearly 40% with temperature from 100 K to 400 K, which is due to the enhanced phonon couplings from the anharmonicity effect. Analysis of phonon power spectra of all systems is performed to interpret simulation results. Contradictory to the traditional thought that amorphous structures tend to have poor thermal transport capabilities due to the disordered atomic configurations, it is calculated that amorphous silicon and silica substrates facilitate the interfacial thermal transport compared with their crystalline structures. Besides, the coupling effect from substrates can improve the interface thermal transport up to 43.5% for coupling strengths χ from 1.0 to 2.0. Our results provide fundamental knowledge and rational guidelines for the design and development of the next-generation silicene-based nanoelectronics and thermal interface materials.

Thermal Conductivity of Amorphous Materials

“…Significantly different, at the a‐Si/a‐Ge interface, this highly interacting frequency range of 12–13 THz shifts to a broader frequency range of vibrations around 10–14 THz, with all the vibrational modes in this wide range contributing approximately equally to the interfacial thermal transport. In addition, similar phenomena of lower thermal resistance at the amorphous interface than that at the crystalline interface was also found in the work of Zhang et al They studied the interfacial thermal transport across silicene and various substrates (c‐Si, a‐Si, c‐SiO 2 , and a‐SiO 2 ) using classical MD simulations. They found that the ITR decreases monotonically with temperature.…”

Energy coupling across low-dimensional contact interfaces at the atomic scale

“…Since the only energy dissipation channel in the heterostructure is through the heated monolayer to the substrate, correlations between the temperature difference and energy evolution can be used to calculate the interfacial thermal resistance without the awareness of specific heat. This technique has been used in our research to study the interfacial thermal transport across graphene-h-BN [80], graphene-phosphorene [81], graphene-stanene [82], silicene-silicon [83], graphene-silicon [84] and graphene-copper [85] interfaces. Compared to the NEMD method, the transient technique focuses on the dynamic response of the hybrid system and therefore can greatly reduce the computation time.…”

Phonon thermal conductivity reduction in silicene nanotubes with isotope substitution

“…The effects of strain, interface, defect, surface functionalization, and size on the thermal conductivity of silicene nanoribbons have attracted considerable attention in the last decade. [20][21][22][23] Despite extensive studies on the electronic and thermal features of silicene nanoribbons, minimal research has been devoted to date to the thermal (phonon) transport of silicene nanotubes (SNTs). 24 Previous studies have shown that isotope impurities provide a powerful technique to modulate the phonon-related properties of carbon nanotubes (CNTs), 25 graphene, 26 and silicon nanowires.…”