Influence of Burstein-Moss effect on photoexcitation and heating of silicon by short and ultrashort laser pulses at wavelength 1.06 μm

摘要

The theoretical research of the influence of Burstein-Moss effect (the effect of interband absorption saturation in semiconductors) on the processes of photoexcitation and heating of monocrystalline silicon under pulsed laser action with pulse durations in the range from hundreds of femtoseconds to hundreds of nanoseconds at the wavelength near the edge of interband absorption (1.06 mu m) was conducted. It was shown that interband absorption saturation effect has the largest impact for picosecond laser pulses. Taking this effect into account in the model presented in this work allows to bring calculated melting thresholds for silicon in accordance with experimental results for wide range of pulse durations. Also, the influence of the effect of band edges filling by carriers during electron-phonon relaxation on the absorption of the second pulse when irradiating using double-pulse femtosecond laser action technique was studied.