Abstract: Semiconductor crystals, especially silicon semiconductor crystals, are doped using a solution to which there are added a silicon dioxide film forming material, a p or n doping material and organic solvent, by applying this solution to the surface of the semiconductor crystals drying and calcining while forming a cohesive, adhering coating layer, and diffusing the doping material into the semiconductor crystals in the calcining. The improvement is using as the silicon dioxide film forming components acidified solutions of partially hydrolyzed alkyl and/or polysilicates, the solutions having a pH between 2 and 6.