Free-carrier generation dynamics induced by ultrashort intense terahertz pulses in silicon

We report the results of experimental studies and numerical simulation of the dynamics of the electron-hole pairs formation in silicon under the action of a two-period terahertz pulse with a maximum electric field strength of up to 23 MV/cm. It is shown that an inhomogeneous distribution of the charge carrier concentration over the depth of the silicon sample is formed, which persists for several microseconds. This inhomogeneity is formed due to a sharp increase in the rate of filling the conduction band with free carriers in the subsurface input layer of the silicon wafer, which occurs at a field strength above 15 MV/cm. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

The study demonstrates that under the action of high-intensity terahertz pulses, an inhomogeneous distribution of charge carrier concentration is formed in silicon, which persists for several microseconds. This inhomogeneity is attributed to a sharp increase in the rate of filling the conduction band with free carriers in the subsurface input layer of the silicon wafer at field strengths above 15 MV/cm.