Phosphor-doped nc-Si:H(nc-Si:H(P)) films were obtained by plasma enhanced chemical vapor deposition.The structural characteristics of nc-Si:H(P) films were investigated by means of scanning tunneling microscopy、Raman scattering,Fourier transform,infrared absorption spectroscopy, electron spin resonance and resonant nuclear reaction techniques.The measurements showed that the nc-Si:H(P) films have two-phase structure and the grains were embedded in the amorphous matrix.It was found that the grain size of the nc-Si:H(P) films was about 25—45nm,whichwas smaller than that of nc-Si:H films (about 3—6nm).It was also found that the optical absorption coefficient was quite high and the optical gap Eoptg was in a range of 173—178eV，which was almost the same as that of nc-Si:H films.The conductivity of nc-Si:H(P) films was in the range of 10-1—101Ω-1·cm-1,two magnitudes higher than that of nc-Si:H films and the maximum room-temperature conductivity reached to 505Ω-1·cm-1.The activation energy of conductivity of the nc-Si:H(P) films was in the range of 001—003eV，lower than that of nc-Si:H film.