Decay dynamics of visible luminescence in amorphous silicon nanoparticles

We have studied the recombination dynamics of carriers in amorphous silicon (a-Si) nanoparticles prepared by electrochemical anodization of hydrogenated a-Si films. The photoluminescence (PL) lifetime of the fast-decay component in a-Si nanoparticles is shorter than that in crystalline silicon (c-Si) nanoparticles. The energy dependence of the PL lifetime in a-Si nanoparticles is different from that in c-Si nanoparticles. The PL decay dynamics of a-Si nanoparticles is determined by recombination processes of carriers localized in the band-tail state. The origin of the blueshift of the PL spectrum in a-Si nanoparticles will be discussed.