The electrical properties of the n-3C-SiC/p-Si heterojunction grown by solid source molecular beam epitaxy on germanium-modified Si(1 1 1) substrates have been investigated. The current flow in the forward direction is determined by diffusion and recombination currents. The interface state density was determined to be not larger than 10(11) cm(-2). The obtained interface state density is lower than in the case of 3C-SiC grown on Si(1 1 1) by chemical vapour deposition. Ce predeposition on silicon prior to silicon carbide is able to improve the ideality factor of the diode and decreases currents of the reverse biassed n-3C-SiC/p-Si heterojunction diode.