Thermal rectification optimization in nanoporous Si using Monte Carlo simulations

Abstract

We investigate thermal rectification in nanoporous silicon using a semi-classical Monte Carlo (MC) simulation method. We consider geometrically asymmetric nanoporous structures, and investigate the combined effects of porosity, inter-pore distance, and pore position relative to the device boundaries. Two basis geometries are considered, one in which the pores are arranged in rectangular arrays, and ones in which they form triangular arrangements. We show that systems: i) with denser, compressed pore arrangements (i.e with smaller inter-pore distances), ii) with pores positioned closer to the device edge/contact, and iii) with pores in a triangular arrangement, can achieve rectification of over 55%. Introducing smaller pores into existing porous geometries in a hierarchical fashion increases rectification even further to over 60%. Importantly, for the structures we simulate, we show that sharp rectifying junctions, separating regions of long from short phonon mean-free-paths are more beneficial for rectification than spreading the asymmetry throughout the material along the heat direction in a graded fashion.

29 pages, 8 figures

References in corpus (13)

• Controlling the energy flow in nonlinear lattices: a model for a thermal rectifier
• An oxide thermal rectifier
• Monte Carlo transient phonons transport in silicon and germanium at nanoscales
• Thermal rectification in bulk materials with asymmetric shape
• Dominant electron-phonon scattering mechanisms in $n$-type PbTe from first principles
• Thermal rectification in thickness-asymmetric graphene nanoribbons
• On the Best Bandstructure for Thermoelectric Performance
• Thermal conductivity of silicon nanomeshes: Effects of porosity and roughness
• Monte Carlo phonon transport simulations in hierarchically disordered silicon nanostructures
• Thermal transport in 2D and 3D nanowire networks
• Large-scale molecular dynamics investigation of geometrical features in nanoporous Si
• Enhanced Phonon Boundary Scattering at High Temperatures in Hierarchically Disordered Nanostructures
• Phonon Bottleneck Identification in Disordered Nanoporous Materials

Cited by in corpus (1)

• Computationally efficient Monte Carlo electron transport algorithm for nanostructured thermoelectric material configurations