We investigated the possibility to use the photoluminescence (PL) emission at room temperature for the characterization of grain boundary and surface passivation of μc-Si and single crystalline silicon. The PL-spectra of c-Si and μc-Si taken at 300 K consist of an emission band around 1.1 and 1 eV, respectively. Measuring the PL intensity we study the influence of electrochemical and plasma passivation by hydrogen. We compare the behavior of the films to that of Si crystals. In this case the PL intensity is high for a well H-terminated c-Si surface and decreases during cathodic polarization (hydrogen evolution) which points to the formation of additional non-radiative recombination centers. Whereas the PL intensity of the as prepared μc-Si films is unchanged, that of the annealed films increases during hydrogen evolution indicating the electrochemical passivation of defects on grain boundaries.