[8a-A410-1~8] 3.7 Laser processing

[8a-A410-5] Effect of the plasma formation in double pulse excitation of 3C-SiC

〇Tomohito Otobe¹ (1.QST)

Keywords:Femtosecond laser processing, Time-dependent density functional theory

This study aims to elucidate the 2-pulse irradiation excitation process of 3C-SiC by first principles simulation based on time dependent density functional theory (TDDFT). First we simply simulated two pulses at 800 nm. Next, different temperatures of valence and conduction bands were calculated from DFT and used as initial wave functions for TDDFT. This corresponds to the excitation in the time period (several tens of fs) before the electron-hole interaction occurs. Next, the initial wave function was calculated by the finite temperature DFT which reproduces the excitation energy by the first pulse, and the electronic excitation by the second pulse was calculated. This is a state in which electron and hole are concentrated on the lower part and the upper part of the band, respectively, and it corresponds to the irradiation after several hundred fs. As a result, the absorption efficiency of the second pulse was highest in the initial distribution by one temperature, the calculation with the finite temperature by the two temperatures as the initial distribution, and finally the two pulse irradiation by TDDFT.