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.