Quantum dot encapsulation techniques
Quantum dots and methods of making quantum dots are described. A method begins with forming quantum dots having a core-shell structure with a plurality of ligands on the shell structure. The method includes exchanging the plurality of ligands with a plurality of second ligands. The plurality of second ligands have a weaker binding affinity to the shell structure than the plurality of first ligands. The plurality of second ligands are then exchanged with hydrolyzed alkoxysilane to form a monolayer of hydrolyzed alkoxysilane on a surface of the shell structure. The method includes forming a barrier layer around the shell structure by using the hydrolyzed alkoxysilane as a nucleation center.
1. A method of making indium phosphide quantum dots, the method comprising:
forming quantum dots having a core comprising indium phosphide (InP), a shell structure comprising zinc sulfide (ZnS) or zinc selenide (ZnSe), and having a plurality of first ligands bound to the shell structure;
exchanging the plurality of first ligands with a plurality of second ligands, wherein the plurality of second ligands have a weaker binding affinity to the shell structure than the plurality of first ligands;
exchanging the plurality of second ligands with hydrolyzed alkoxysilane to form a monolayer of hydrolyzed alkoxysilane on a surface of the shell structure; and
forming a barrier layer around the shell structure by using the hydrolyzed alkoxysilane as a nucleation center.
2. The method of claim 1 , wherein the plurality of first ligands comprises carboxylic acid.
3. The method of claim 1 , wherein the plurality of first ligands comprises alkanethiols.
4. The method of claim 1 , wherein the plurality of second ligands comprises oleylamine.
5. The method of claim 1 , wherein the plurality of second ligands comprises aliphatic amines.
6. The method of claim 1 , wherein the plurality of second ligands comprises alkylphosphines.
7. The method of claim 1 , wherein the plurality of second ligands comprises polyethylene glycol alkyl ether or polyethylene glycol aryl ether.
8. The method of claim 1 , wherein the barrier layer comprises an oxide.
9. The method of claim 8 , wherein the barrier layer comprises silicon dioxide.