Time-Resolved Luminescence of Porous Si and InP

Abstract

The kinetics of porous Si and InP luminescence has been investigated using short (10 ps, 2 ns and 14 ns) laser pulses for excitation, by a streak camera with 10 ps time-resolution and photomultiplier for measuring fast and slow increase and decay of the intensity of luminescence. Two luminescence bands with fast and slow decay have been registered within the usually observed single wide band in the time-resolved photoluminescence spectra of porous Si and attributed to the recombination via free excitons and the surface states in nanostructures. The time-resolved intensity of porous InP luminescence has been measured at different intensities of laser excitation. At high excitation the intensity of photoluminescence has a relatively slow increase and complicated decay. The change of the kinetic properties has been explained by numerous processes in semiconductor–dielectric quantum wires and dots: the slowing down of intraband relaxation, collective exciton–exciton (electron) interaction, Auger recombination, etc.