Disclosed herein are heterostructure semiconductor nanowires. The heterostructure semiconductor nanowires comprise semiconductor nanocrystal seeds and semiconductor nanocrystal wires grown in a selected direction from the surface of the semiconductor nanocrystal seeds wherein the semiconductor nanocrystal seeds have a composition different from that of the semiconductor nanocrystal wires. Further disclosed is a method for producing the heterostructure semiconductor nanowires.