Exciton Lifetime in Sio_2 Layers with Embedded Silicon Nanocrystals as a Function of the 'Dark' Fraction Of Nanocrystals in the System

摘要

Previously reported data on photoluminescence quenching in ion-beam irradiated silicon dioxide layers with embedded silicon nanocrystals were used to analyze the exciton lifetime in such systems versus the quenched fraction of nanocrystals. Estimates of the characteristic time of exciton hopping between adjacent nanocrystal grains, the length of excitonic wavefunction decay into the dielectric, and the cross-section of exciton recombination at deep-level centers introduced by the irradiation into the SiO_2 matrix are given.