Quantum dots with a III-V core and an alloyed II-VI external shell
AssigneeQustomDot B.V.
InventorsZeger Hens, Mickael Tessier, Dorian Dupont
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Abstract
This disclosure relates to quantum dots with a core of III-V material, a first layer of II-VI material and an external shell of II-VI material to be used, for example, in downconverters. The external shell is preferably made of an alloy of Zn and Cd with Se or S. The inventors have demonstrated that introducing a small amount of Cd in the external shell provides excellent absorbance performance in blue, violet and UV wavelengths. The amount of Cd needed for this increase in absorbance can be very low. The inventors have shown that the emitted light can be nearly monochromatic, which is especially interesting in electronic applications.
Claims18
Quantum dot comprising:
- a core of a binary, ternary or quaternary III-V material consisting of:
- at least one element selected from the group consisting of In, Ga and Al, and
- at least one element selected from the group consisting of P and As;
- a first layer of a binary or ternary II-VI material consisting of:
- Zn, and
- at least one element selected from the group consisting of S and Se;
- and
- an external shell of a ternary or quaternary II-VI material consisting of:
- Zn,
- Cd, and
- at least one element selected from the group consisting of S and Se,
- wherein said quantum dot further comprises a ligand layer comprising thiol molecules.
Process for producing a quantum dot comprising the steps of:
- (a) producing a core nanocrystal of a binary, ternary or quaternary III-V material consisting of:
- at least one element selected from the group consisting of In, Ga and Al, and
- at least one element selected from the group consisting of P and As;
- (b) forming a first layer on the core nanocrystal, the first layer being of a binary or ternary II-VI material consisting of:
- Zn, and
- at least one element selected from the group consisting of S and Se;
- (c) forming an external shell on the first layer, the external shell being of a ternary or quaternary II-VI material consisting of:
- Zn
- Cd, and
- at least one element selected from the group consisting of S and Se;
- and
- (d) adding a thiol compound to a solution resulting from step (c).
Dependencies are inferred from the claim text.