Study of ultrafast lattice dynamics in silicon using Three-Temperature model

We would like to present a new Three-Temperature model (3TM) based on nTTM, to calculate electron, hole and lattice temperatures separately. The model calculates the single and double photon absorption by including the effect of band structure re-normalization. Drude model is used to calculate the dielectric function, including the effect of electron-hole and carrier-phonon collisions. Maxwell\u27s equations are solved using Finite Difference Time Domain (FDTD) method to describe the laser field. A comparison of experimental thresholds from Allenspacher et. al. (Proc. SPIE, 4932:358, 2003), with theoretical results for a 775 nm pulse is done. Damage in silicon may be due to thermal effects and electron emission from surface, depending on the incident pulse duration. 3TM calculations also hold up for different pulse wavelengths, making it a promising tool to study laser excitation. 3TM can be of significant use in quantifying the damage mechanisms and in manipulating laser parameters and optical properties of material to induce desired structural modifications.The 69th JSAP Spring meeting 202