Ultrafast laser spectroscopy of semiconductor nanocrystals

A large amount of work has been worldwide directed to understand the properties of semiconductor nanostructures. Ultrafast lasers with pulsewidths of a few femtoseconds allowed the investigation of the dynamics of elementary excitations in semiconductor structures on ultrashort time scales. Recent progress in technology made it possible to fabricate semiconductor nanocrystals (i.e. crystals of nanometer dimensions) of well-defined properties. The purpose of this paper is to review the understanding of carrier relaxation and recombination processes in semiconductor nanocrystals as studied by ultrafast laser spectroscopy. The up-to-date techniques of ultrafast laser spectroscopy as well as the fabrication of semiconductor nanocrystals are discussed in some detail.