Radiative phonon transport in silicon and collisional energy transfer in aluminum films due to laser short-pulse heating: Influence of laser pulse intensity on temperature distribution

Energy transfer across aluminum and silicon films through phonon transport is examined in line with the laser short-pulse interaction with the aluminum film. The modified two-equation model is incorporated to compute electron and lattice site temperatures in the aluminum film while phonon radiative transport is used to predict equilibrium temperature in the silicon film. The thermal boundary resistance is considered at the interface of the films in the analysis. The numerical scheme using the finite difference method is adopted to solve the governing equations of energy. It is found that lattice site temperature rise is gradual in the aluminum film in the late heating period. However, equilibrium temperature decay is sharp in the region of silicon interface during this period. The thermal boundary resistance lowers lattice site temperature considerably in the region of the aluminum interface.

► Thermal boundary resistance lowers lattice site temperature considerably at interface region in the aluminum film.
► Decay of equilibrium equivalent temperature is gradual towards the back surface of the silicon film.
► Equilibrium temperature reduces more at silicon interface for high laser power intensities.
► Temperature jump takes place at silicon film interface because of the phonon emission.