Thermal Rectification of Silicene Nanosheets With Triangular Cavities by Molecular Dynamics Simulations

Abstract

Silicene, the silicon-based two-dimensional structure with honeycomb lattice, has been discovered and expected to have tremendous application potential in fundamental industries. However, its thermal transport mechanism and thermal properties of silicene have not been fully explained. We report a possible way to control the thermal transport and thermal rectification in silicene nanosheets by distributing triangular cavities, which are arranged in a staggered way. The nonequilibrium molecular dynamics (NEMD) simulation method is used. The influences of the size, number, and distribution of cavities are investigated. The simulation results show that reflections of phonon at the vertex and the base of the triangular cavities are quite different. The heat flux is higher when heat flow is from the vertex to the base of cavities, resulting in thermal rectification effect. The thermal rectification effect is strengthened with increasing cavity size and number. A maximum of thermal rectification with varying distance between columns of cavities is observed.

Thermal rectification induced by Wenzel–Cassie wetting state transition on nano-structured solid–liquid interfaces

“…[9,10] In the past decades, the thermal rectification phenomenon has been investigated in solid materials with asymmetric structures. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] In 1936, the thermal rectification phenomenon has been reported in a system with copper/cuprous oxide interface, which is caused by the electron-phonon scattering at the interface. [11] Then, several thermal rectification mechanisms have been proposed, including the thermal potential barrier at the interface, [12] temperature-dependent interfacial thermal resistance or bulk thermal conductivity, [13,14] asymmetric nanostructures, [15] and electron transfer.…”

“…[21,22] However, the primary drawbacks of thermal rectification in solid lattice systems are manufacturing difficulty. [23][24][25][26][27][28][29] Recently, thermal rectification through solid-liquid (S-L) interfaces has been proposed, wherein the thermal rectification can be manipulated by varying the temperature and pressure of the system. [30][31][32][33][34][35][36][37] In Ref.…”

The control of thermal conductivity through coherent and incoherent phonon scattering in 2-dimensional phononic crystals by incorporating elements of self-similarity

“…The wave scattering results in a modification of the allowed frequencies of the phonons in the different directions of the artificial phononic crystal which in turn alters the thermal conductivity, 𝜅 of the host material. The use of two-dimensional PnC for the suppression of 𝜅 has been increasing not only for engineered thermoelectric materials [1][2][3][4][5][6], commonly referred to as 'holey silicon' [1], but also for such applications where the sensitivity of chemical and temperature sensors need to be boosted [7,8], for low temperature thermal isolation for various sub-Kelvin applications in physics and astronomy [9,10], in thermal devices [11] and for heat guiding [12]. Irrespective of the targeted application area, there are two possible reasonings put forward for the observed reduction in the thermal conductivity.…”