The origin of the photoluminescence (PL) emitted by silicon powder produced by plasma-enhanced chemical vapor deposition is analyzed in view of the structural changes induced by laser annealing. Both, the Raman spectra and the PL signal are qualitatively different before and after this process. It involves some degree of recrystallization which can be deduced from the Raman spectra and also from a strong emission of H-2. The analysis shows that the characteristic PL does not come from tile as-grown state of the sample but from the annealed state.