Controlled doping of semiconductor nanowires

Abstract

A catalyst particle on a substrate is exposed to reactants containing a semiconductor material in a reactor. An intrinsic semiconductor nanowire having constant lateral dimensions is grown at a low enough temperature so that pyrolysis of the reactant is suppressed on the sidewalls of the intrinsic semiconductor nanowire. Once the intrinsic semiconductor nanowire grows to a desired length, the temperature of the reactor is raised to enable pyrolysis on the sidewalls of the semiconductor nanowire, and thereafter dopants are supplied into the reactor with the reactant. A composite semiconductor nanowire having an intrinsic inner semiconductor nanowire and a doped semiconductor shell is formed. The catalyst particle is removed, followed by an anneal that distributes the dopants uniformly within the volume of the composite semiconductor nanowire, forming a semiconductor nanowire having constant lateral dimensions and a substantially uniform doping.