Abstract

Changes in the transmission of quasi-zerodimensional CdSe and CdSSe nanocrystals (NCs-quantum dots) and quasi-one-dimensional Porous Silicon (quantum wires) induced by ultrashort laser pulses were investigated with picosecond time resolution using pump and probe technique. The transitions between the energy levels of electrons and holes spatially confined within CdSe and CdSSe NCs and wires of Porous Si were observed as bleaching bands in nonlinear transmission spectra. The induced decrease of absorption was explained by filling of states in quantum dots and wires by photoexcited carriers (saturation effect).

© 1994 IEEE