Disclosed herein is a multilayer nanocrystal structure (300) comprising a nanocrystal alloy core (100) comprising two or more nanocrystals (10,50) and including an alloy interlayer (30) formed at an interface between the two or more nanocrystals (10,50), and one or more layers of nanocrystal shells (110,120) formed sequentially on the surface of the nanocrystal alloy core, wherein the nanocrystal shells (110,120) each have different band gaps. The multilayer nanocrystal structure (300) can be applied to various electronic devices owing to its advantages of high luminescence efficiency, superior optical stability, and superior chemical stability.