Thermal resistance and thermal rectification of silicon device with triangular pores: A molecular dynamics study
Introduction
With the rapid development of miniaturization and increasing demand of high-power density of semiconductor devices, it is vital to reveal the dominant rule of thermal conduction in microscale and nanoscale structures. The thermal rectification is an attractive and special heat transfer phenomenon which has the potential for applications in thermal signal processing and thermal management. If the thermal diodes based on the mechanism of thermal rectification can be successfully developed, it will play a significantly important role as the electronic diode does in the modern electronic industry. Conceptually, the thermal rectification refers to that the thermal conductivity or resistance is different when the heat flux directions are opposite. Under the same temperature difference, heat can preferentially run in one direction, but not in the opposite direction. Recently, many studies have been conducted on the behaviors of thermal rectification. However, the mechanism of thermal rectification and the parameters that dominate the thermal rectification phenomenon need to be further investigated.
The thermal rectification phenomenon was first investigated at the solid-solid interface [1], [2], [3]. The thermal potential barrier existing at the interface of two different thermal conductivity material is found to cause the thermal rectification phenomenon. Rajabpour [4] investigated the thermal rectification in graphene and graphene nanoribbons. There exists a Kaptiza resistance in the interface between the graphene and graphene nanoribbons, which causes the thermal rectification phenomenon. Liu [5] studied the interface thermal conductance between the hybrid graphene/silicene heterostructures and found that the interface thermal conductance depends on the heat flux direction indicating the existence of the thermal rectification at the interface. The interfacial thermal resistance was also investigated by Wang [6], [7] in bi-layer nanofilm of argon type materials to explore the corresponding mechanism, and it was found that the interfacial thermal resistance depends on the temperature difference and the atomic mass ratio. For nanoscale structures, it is the unique thermal properties which play important roles in leading to the thermal rectification. Besides the interface between two dissimilar materials, the factors like grade mass density, asymmetric geometries and temperature dependent conductivity can also trigger the thermal rectification phenomenon [8]. Alaghemandi [9] established a set of mass-graded nanosized model system with four carbon nanotubes on one side and a single one carbon nanotube on the other side and the thermal rectification phenomenon was detected in the externally mass-loaded nanotubes. Yuan [10] studied the thermal rectification in hybrid pristine and silicon-functionalized graphene nanoribbons and found that the thermal rectification factor can be adjusted by the Si/C ratio and silicon distribution. Through the hybrid pristine and hydrogenated carbon nanotube structures, Goridiz [11] also found the thermal rectification behavior and investigated the influence of two main factors, namely, the hydrogen coverage and the diameters of the nanotubes.
Among the above-mentioned factors that affect the thermal rectification [12], [13], [14], [15], [16], [17], [18], [19], [20], the adoption of asymmetric geometries is a good way to control the thermal rectification phenomenon because that the possible thermal rectifier device can be realized with only one material system. By designing triangular cavities in silicene nanosheets and silicon nanofilm, the thermal rectification phenomenon was explored by Liang [21], [22]. Moreover, Liang [23] investigated the thermal rectification in asymmetric silicon nanoribbons in which the width of the thin end of the structure was not fixed at a constant value but varies from 1 unit cell to 5 unit cells. The results indicated that when the heat flows from the thin end to the thick end, the thermal conductivity becomes apparently larger. Ruan [24] demonstrated the thermal rectification effect in asymmetrically graphenen nanoribbons through defect engineering and analyzed the influences of the Single-Vacancy defect, Di-Vacancy defect, Substitutional silicon defect and Stone-Wales defect on the thermal rectification. In general, the above-mentioned simulations demonstrated that the spatial asymmetry in geometry is a key factor to achieve the thermal rectification.
In recent years, many theoretical studies on thermal rectification were conducted using the molecular dynamic (MD) simulation methods [25], [26], [27], [28], [29], [30], [31] and the main research was focused on the graphenen-based systems. Silicon materials as highly efficient thermoelectric materials have great potentials to be used in the fabrication of the silicon-on-insulator (SOI) devices and microelectromechanical systems (MEMS) [32], [33], [34]. Considering the advantages of the thermoelectric properties of semiconductor silicon materials, they will play important roles in thermal signal processing and thermal management. Therefore, the silicon material is a good candidate for the thermal rectifier. Compared with the comprehensive research on the thermal rectification of graphene-based structures, the thermal rectification of silicon-based structures still needs to be further explored and the asymmetric geometries effect should be fully understood.
In this paper, the heat transport in the silicon device with triangular pores is investigated. The reverse nonequilibrium molecular dynamics (RNEMD) method is adopted to simulate the equivalent thermal resistance of the triangular pores and thermal conductivity at the temperature of 300 K. The thermal rectification phenomenon was observed in such silicon device with pores. Furthermore, parametric analysis was thoroughly conducted to reveal the influences of the angles and the distribution of triangular pores on the equivalent thermal resistance and the thermal rectification. This work provides a practice choice for the design of the thermal rectifier in silicon device.
Section snippets
Model and methodology
The schematic of the silicon configuration with triangular pore is shown Fig. 1. The length, width and thickness of the simulated silicon device are 65.17 nm, 21.72 nm and 1.09 nm, respectively. The designed pore is set in the shape of isosceles triangle, that is, the structure is symmetric about its horizontal axis. To investigate the effect of the triangular pore shape on thermal rectification, the vertex angle α varies from 40° to 120° with a constant value in height ( in Fig. 1) of 4.33
Results and discussion
Firstly, we tested the accuracy of the RNEMD simulation by calculating the thermal conductivity of the silicon device with no pores. The simulated thermal conductivity is about 13.87 W/(m K) at the temperature of 300 K with the device thickness of 1.09 nm, which is in good agreement with the thermal conductivity of silicon film reported by using the different calculating method [41], [42].
Conclusions
In this paper, the equivalent thermal resistance of pores and the thermal conductivity of the silicon device with triangular pores is investigated by the reverse nonequilibrium molecular dynamic method at the temperature of 300 K. The results show that the equivalent thermal resistance is affected by the heat flux direction, and it is found that larger equivalent thermal resistance can be achieved when the heat flows along the x-direction (that is, from the base to the vertex of the triangular
CRediT authorship contribution statement
Jia Chen: Data curation, Investigation, Methodology, Software, Validation, Visualization, Writing – original draft. Xiaobing Zhang: Conceptualization, Supervision, Writing – review & editing.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
This work is supported by the National Natural Science Foundation of China (Grant No.12072160).
References (42)
- et al.
A review of thermal rectification observations and models in solid materials
International Journal of Thermal Sciences
(2011) - et al.
Interface thermal conductance and rectification in hybrid graphene/silicene monolayer
Carbon.
(2014) - et al.
Investigation of thermal rectification in bi-layer nanofilm by molecular dynamics
International Journal of Thermal Sciences
(2011) - et al.
Tunable thermal rectification in silicon-functionalized graphene nanoribbons by molecular dynamics simulation
International Journal of Thermal sciences.
(2015) - et al.
Thermal rectification of a single-wall carbon nanotube: a molecular dynamics study
Solid State Communications
(2014) - et al.
Thermal rectification assisted by lattice transitions
International Journal of Thermal Sciences
(2014) - et al.
Thermal rectifier efficiency of various bulk-nanoporous silicon devices
International Journal of Heat and Mass Transfer
(2016) - et al.
Transition of thermal rectification in silicon nanocones
Applied Thermal Engineering
(2016) - et al.
Thermal conductivity modeling of micro- and nanoporous silicon
International Journal of Thermal Sciences
(2010) - et al.
Two-dimensional numerical simulation of thermo-electric coupling model in semiconductor bridge ignition system
International Journal of Heat and Mass Transfer
(2017)
Pore-size dependence of the heat conduction in porous silicon and phonon spectral energy density analysis
Physics Letters A
Fitting the Stillinger–Weber potential to amorphous silicon
Journal of Non-Crystalline Solids
An investigation of the phonon properties of silicon nanowires
International Journal of Thermal Sciences
Lattice dynamics analysis of thermal conductivity in silicon nanoscale film
Applied Thermal Engineering
Heat flow asymmetry on a junction of quartz with graphite
Physica Status Solidi (a)
Heat flux rectification in tin-a-brass system
Physica Status Solidi (a)
Interface thermal resistance and thermal rectification in hybrid graphene-graphane nanoribbons: a nonequilibrium molecular dynamics study
Applied Physics Letters.
Investigation of interfacial thermal resistance of bi-layer nanofilms by nonequilibrium molecular dynamics
Journal of Physics D: Applied Physics
Thermal rectification in mass-graded nanotubes: a model approach in the framework of reverse non-equilibrium molecular dynamics simulations
Nanotechnology
Thermal rectification in nanosized model systems: a molecular dynamics approach
Physical Review B
Thermal rectification in pristine-hydrogenated carbon nanotube junction: a molecular dynamics study
Journal of Applied Physics
Cited by (1)
Progress in thermal rectification due to heat conduction in micro/nano solids
2023, Materials Today PhysicsCitation Excerpt :The influence of porosity on the thermal rectification coefficient is similar to that of doping concentration, and the thermal rectification coefficient increases with the increase of porosity, because phonon-hole scattering is more intense at large porosity. In 2021, Chen et al. [94] studied thermal rectification generated by triangular hole vacancies in silicon devices through MD, as shown in Fig. 5(d). The vertex angle and hole arrangement of the triangular vacancy both affect the thermal rectification because the triangular vacancy causes the difference of thermal resistance when the heat flow passes in different directions.