High speed preparation of A1/nip/SnO2/indium tin oxide/Glass type amorphous Si solar cells from disilane is presented with emphasis on the boron doping profile during the intrinsic layer deposition. It was found that the cell characteristics strongly depend on the doping level and the profile of B2H6, and 8.05% and 6.85% conversion efficiencies were obtained with a linear graded doping profile at the deposition rates of 15 and 30 A˚/s, respectively.