Monte Carlo transient phonons transport in silicon and germanium at nanoscales

Abstract

Heat transport at nanoscales in semiconductors is investigated with a statistical method. The Boltzmann Transport Equation (BTE) which characterize phonons motion and interaction within the crystal lattice has been simulated with a Monte Carlo technique. Our model takes into account media frequency properties through the dispersion curves for longitudinal and transverse acoustic branches. The BTE collisional term involving phonons scattering processes is simulated with the Relaxation Times Approximation theory. A new distribution function accounting for the collisional processes has been developed in order to respect energy conservation during phonons scattering events. This non deterministic approach provides satisfactory results in what concerns phonons transport in both ballistic and diffusion regimes. The simulation code has been tested with silicon and germanium thin films; temperature propagation within samples is presented and compared to analytical solutions (in the diffusion regime). The two materials bulk thermal conductivity is retrieved for temperature ranging between 100 K and 500 K. Heat transfer within a plane wall with a large thermal gradient (250 K-500 K) is proposed in order to expose the model ability to simulate conductivity thermal dependence on heat exchange at nanoscales. Finally, size effects and validity of heat conduction law are investigated for several slab thicknesses.

Cited by in corpus (28)

• Efficient simulation of multidimensional phonon transport using energy-based variance-reduced Monte Carlo formulations
• Heat conduction tuning using the wave nature of phonons
• Steady-State Heat Transport: Ballistic-to-Diffusive with Fourier's Law
• Universal features of phonon transport in nanowires with correlated surface roughness
• Thermal conductivity of silicon nanomeshes: Effects of porosity and roughness
• Extending the range of validity of Fourier's law into the kinetic transport regime via asymptotic solution of the phonon Boltzmann transport equation
• A Simple Boltzmann Transport Equation for Ballistic to Diffusive Transient Heat Transport
• Monte Carlo phonon transport simulations in hierarchically disordered silicon nanostructures
• Modeling semi-conductor thermal properties. The dispersion role
• MCBTE: A variance-reduced Monte Carlo solution of the linearized Boltzmann transport equation for phonons
• Ultrathin GaN Nanowires: Electronic, Thermal, and Thermoelectric Properties
• Rayleigh waves, surface disorder, and phonon localization in nanostructures
• Hierarchically nanostructured thermoelectric materials: Challenges and opportunities for improved power factors
• Enhanced Phonon Boundary Scattering at High Temperatures in Hierarchically Disordered Nanostructures
• Thermal rectification optimization in nanoporous Si using Monte Carlo simulations
• Thermal conductivity of disordered porous membranes
• Heat transfer in rough nanofilms and nanowires using Full Band Ab Initio Monte Carlo simulation
• Thermoelectric Studies of Nanoporous Thin Films with Adjusted Pore-Edge Charges
• Computationally efficient Monte Carlo electron transport algorithm for nanostructured thermoelectric material configurations
• Analytical Green's Function of Multidimensional Boltzmann Transport Equation for Modeling Hydrodynamic Second Sound
• Experimental observation of moving intrinsic localized modes in germanium
• Physics-Informed Neural Networks for Solving Multiscale Mode-Resolved Phonon Boltzmann Transport Equation
• A fast synthetic iterative scheme for the stationary phonon Boltzmann transport equation
• Discrete unified gas kinetic scheme for multiscale heat transfer with arbitrary temperature difference
• An implicit kinetic scheme for multiscale heat transfer problem accounting for phonon dispersion and polarization
• Revisiting thermal conductivity and interface conductance at the nanoscale
• Quantitatively Predicting Modal Thermal Conductivity of Nanocrystalline Si by full band Monte Carlo simulations
• Effects of ballistic transport on the thermal resistance and temperature profile in nanowires