Charge carrier dynamics at the SiO2/Si(100) surface: a time-resolved photoemission study with combined laser and synchrotron radiation

Abstract

Abstract The charge carrier dynamics at a thermally grown 15 A thick SiO 2 /Si(1 0 0) interface has been studied by time-resolved Si 2p core level photoemission. Upon excitation of electron hole pairs in the surface-near region by picosecond laser pulses, the dynamics of the charge carrier recombination has been determined by time-resolved Si 2p core level photoemission via the time-dependent surface photovoltage. On a timescale from picoseconds to 800 ns a non-exponential decay of the surface photovoltage and a logarithmic dependence on laser intensity is found. Both aspects can be well described by a quasi-equilibrium model based on charge carrier dynamics which is governed by thermionic emission.