Abstract: Boron-doped a-Si:H films are expected to be used as the photo-conductive layer in Liquid Crystal Light Valve. Using hydrogen-diluted SiH₄ and B₂H₆ as the precursor gases, boron-doped a- Si:H films were obtained by the plasma-enhanced Chemical Vapor Deposition. According to the results from X-ray diffraction, Atom Force Microscopy, and photo/dark conductivity measurements,the doping of boron increases the room-temperature dark conductivity, decreases the photo/dark conductivity ratio and enhances the crystallization in amorphous silicon films. Results from FTIR measurement indicate that various kinds of complex might be formed among boron, silicon, and hydrogen atoms. Only a small amount of boron atoms devotes to the acceptor doping in boron-doped a-Si:H films.