Modeling of the temperature field in the amorphous Ge2Sb2Te5 film induced by a picosecond laser with a body heat source

Three-dimensional body-heating finite element method simulation was carried out to study the temperature field of the amorphous Ge2Sb2Te5 film induced by picosecond laser pulse. In the model, the continuous medium heat conduction theory with semi-infinity heat conduction was employed together with the assumption of the Gaussian temporal and spatial profiles. The verification between the prediction and experiment showed that simulated results reasonably agreed with experimental observations. Based on the simulation, it showed that the maximum temperature appeared at the top surface center, and the variation of temperature field within the whole film followed the same trend. Characteristics of the temperature field between the thin and thick films were further compared. A relatively homogeneous temperature field along the thickness direction was obtained for the case of thin film where thermal equilibrium reaches quickly. The total absorbed energy by the Ge2Sb2Te5 film increased with the increase of film thickness, however, the predicted maximum temperature at the top surface center declines with the increment of film thickness, which is affected by thermal conduction.