C. Delerue et al., Electron-phonon coupling and optical transitions for indirect-gap semiconductor nanocrystals - art. no. 193402, PHYS REV B, 6419(19), 2001, pp. 3402
We show that it is possible to perform full microscopic calculations of the
phonon-assisted and no-phonon radiative transitions in silicon nanocrystal
s. These are based on a tight-binding Hamiltonian for the electron and elec
tron-phonon part together with a valence force-field model for phonons. We
predict an unexpected large broadening of the luminescence peaks attributed
to the breaking of bulk selection rules and to multiphonon effects in the
acoustic range. We also find that phonon-assisted transitions dominate over
the full range of sizes. These results are compared to previous estimates
in the effective-mass approximation and are used to discuss available exper
imental data.