Highly uniform silicon/germanium nanoparticles can be formed into stable dispersions with a desirable small secondary particle size. The silicon/germanium particles can be surface modified to form the dispersions. The silicon/germanium nanoparticles can be doped to change the particle properties. The dispersions can be printed as an ink for appropriate applications. The dispersions can be used to form selectively doped deposits of semiconductor materials such as for the formation of photovoltaic cells or for the formation of printed electronic circuits.