The effect of size distributions of Si nanoclusters on photoluminescence from ensembles of Si nanoclusters

We use a method similar to those of Kane and the quantum confinement model to obtain the photoluminescence (PL) spectra from ensembles of Si nanoclusters. The diameters (d) of Si nanoclusters in ensembles are considered with a Gaussian distribution. Our work demonstrates that (1) a PL spectrum with a line-shape asymmetry on the wavelength (or energy) scale is in agreement with experiments; (2) a red-shift in the PL peak can be found due to the size distribution and thus used to obtain the physically reasonable exciton binding energy; (3) the broadening of the PL spectra may be partially due to the electron-phonon interaction, the temperature effect as well as the shape effect of the Si nanocluster.