Preparation of nanorods

A method of preparing a core-shell nanorod comprising growing a shell of a core-shell nanorod (M1X1)M2X2 in a solution through a slow-injection of M2 precursor solution and X2 precursor solution to a suspension of M1X1 nanocrystals to form the shell in a first shell growth step, and, after stopping the first shell growth step, further growing the shell of the core-shell nanorod (M1X1)M2X2 in the solution through a slow-injection of M2 precursor solution and X2 precursor solution to a suspension of M1X1 nanocrystals to form a thicker shell in a second shell growth step and, wherein the core-shell nanorod includes a M1X1 core.