Thermal Energy Transport across Combined Films: Thermal Characteristics

Thermal energy transfer in combined thin films consisting of silicon and diamond is considered. The combined films are thermally disturbed by a temperature oscillation at the silicon left edge and the influence of pulse length of temperature oscillation on energy transport characteristics is investigated. A nano-size gap with varying length is adopted at the films interface. The Boltzmann equation is adopted for the predictions of phonon intensity in the combined structure. The cut-off mismatch model is accommodated formulating interface conditions. The contribution of the near field radiation, due to evanescent waves, is also included at the interface. Equivalent equilibrium temperature is used quantifying phonon intensity distribution in the combined structure. It is found that the influence of the temperature oscillation on the phonon transport is significant at the silicon interface, i. e., increasing pulse length reduces phonon intensity at the silicon interface. Temporal behavior of equivalent equilibrium temperature is similar to the temperature oscillation introduced at the left edge of the silicon. The rise in temperature in the combined film is faster in the beginning of the heating cycle.