Optical properties of diamond-like carbon and silicon carbide (SiC) films in dependence on deposition conditions were investigated. It was established that the films having refractive index from 1.6 to 2.3 may be obtained. The film optical bandgap and hardness may be changed from 1.5 to 4eV and from similar to1 to similar to20 GPa, correspondingly. The films were deposited onto the front side of silicon solar cells (SCs). It has been shown that deposition of single- or two-layer diamond-like carbon antireflection (AR) coatings enables the SCs efficiency to be improved 1.35-1.5 times. The improvement is connected with decreasing of reflection losses and passivation of recombination active centers. SiC AR coatings improve the solar cell efficiency up to 1.3 times. (C) 2002 Elsevier Science B.V. All rights reserved.