Doping nanowires grown by the vapor-liquid-solid mechanism

The ability to dope semiconductor nanowires during growth is an important step toward making functional devices. We develop a model for steady state vapor-liquid-solid growth of a ternary semiconductor-catalyst-dopant nanowire. Our analysis shows that the relative flux of dopant atoms through the liquid controls the mole fraction of dopant in the solid wire, and that local equilibrium constrains the catalyst composition in the solid and the compositions of the dopant and catalyst in the liquid. We find that the phase diagram can be used to determine an upper limit on the dopant composition in the solid.