Nonlinear spectroscopy and applications: time-resolved nonlinear spectroscopy of silicon nanocrystals

Abstract

We review results we obtained by nonlinear time-resolved laser spectroscopy of silicon nanocrystals. The results of photoluminescence measurements on the femtosecond to microsecond time scales and of the picosecond pump and probe absorption measurements indicate the important role of carrier trapping into nanocrystals surface states and of Auger process in photoexcited carrier relaxation and recombination. The optical response of assemblies of silicon nanocrystals was found to be strongly dependent on the wavelength of the excitation light. The relation between microscopic carrier processes and optical nonlinear properties of the material as well as the impact on possible development of silicon laser are discussed.