Patent ID: 8309170

Claim:
A method for producing a multilayer nanocrystal structure comprising: (a) forming a nanocrystal alloy core comprising two or more nanocrystal layers and including an alloy interlayer formed at an interface between the two or more nanocrystal layers, by forming a first nanocrystal; adding the first nanocrystal to a first precursor of a second nanocrystal, wherein the second nanocrystal is different from the first nanocrystal; adding a second precursor of the second nanocrystal; and growing the second nanocrystal on a surface of the first nanocrystal simultaneously with forming an alloy interlayer at the interface between the first nanocrystal and the second nanocrystal by diffusion of the first nanocrystal and second nanocrystal into each other; and (b) sequentially growing one or more layers of nanocrystal shells, each having different band gaps, on a surface of the nanocrystal alloy core to form the nanocrystal shells such that a first layer of nanocrystal shell completely covers the exposed surface of the nanocrystal alloy core, and each additional layer of nanocrystal shell completely covers an exposed surface of a previous layer of nanocrystal shell; wherein an outermost shell of the nanocrystal shells has a band gap larger than any one band gap of the nanocrystal alloy core, and the inner shell layers have a smaller band gap compared to that of the nanocrystal alloy core.