Recombination kinetics of a dense electron-hole plasma in strontium titanate

Abstract

We investigated the nanosecond-scale time decay of the blue-green light emitted by nominally pure $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ following the absorption of an intense picosecond laser pulse generating a high density of electron-hole pairs. Two independent components are identified in the fluorescence signal that show a different dynamics with varying excitation intensity and which can be modeled as a bimolecular and unimolecolar process. An interpretation of the observed recombination kinetics in terms of interacting electron and hole polarons is proposed.