Chemical role of amines in the colloidal synthesis of CdSe quantum dots and their luminescence properties

Synthesis of nanostructured cadmium and zinc sulfides in aqueous solutions of hyperbranched polyethyleneimine

“…For Cd and Zn, amines represent both complex ligands, in the source solutions, and capping ligands, in product colloidal solutions. On this basis, successful synthesis of QDs of CdSe and ZnO was reported, where the product particle sizes were controlled by the diffusion process depending on the density of adsorption of the amine; and hence on its mass and shape [34,[38][39][40]. These reports show that the synthesis of nanoparticles of transition metal compounds the competing factors are the electron donation ability and the capping density of the amine.…”

“…Amines can act as ligands and form co-ordination bonds to transition metal ions [34][35][36][37][38][39]. This way, they have an important role in the colloidal synthesis of nanoparticles of transition metal compounds for their behavior as capping ligands on the surface of the early formed nanoparticles [34,35].…”

“…This way, they have an important role in the colloidal synthesis of nanoparticles of transition metal compounds for their behavior as capping ligands on the surface of the early formed nanoparticles [34,35]. When present in the medium of precipitation of group IV elements, amines have two functions: (i) the ligand molecules forming the Cd-amine complex in the source solution and (ii) the capping ligand passivating the surface defects of the product QDs [34]. For Cd and Zn, amines represent both complex ligands, in the source solutions, and capping ligands, in product colloidal solutions.…”

Large-Scale Synthesis of Highly Luminescent InP@ZnS Quantum Dots Using Elemental Phosphorus Precursor

“…Thus, the heavier indium−alkylamine complex may diffuse more slowly into the surface layers of growing InP QDs; as a result, smaller QDs are produced. [73] Since OLA (used as a solvent) also acts as a source of surface passivating ligands for QDs, varying its amount may affect the degree of QD surface passivation during the growth stage as well as the size of the resulting QDs. For example, the orange-emitting QDs can be synthesized by using half the amount of OLA, compared with that for yellow-emitting QDs, at 180 °C for 30 min.…”

UV luminescent organic-capped ZnO quantum dots synthesized by alkoxide hydrolysis with dilute water

“…Based on the HREM observation that the heating after the OLA addition causes an increase in the dispersibility, we concluded that the hydroxyl and/or alkoxy group on the surfaces of the QDs should be replaced with OLA during the heating above 100°C. Even when the QDs are capped by BZA, because the BZA capping showed a lower stabilization than OLA that comes from the difference in the electron donation ability of amino group between the aromatic amine and aliphatic amine [25], the increase in dispersibility of the QDs after heating with OLA can be explained by the exchange of the pristine BZA capping for a new OLA capping. Therefore, we successfully obtained OLA-capped ZnO QDs that are colloidally dispersible in a nonpolar organic solvent, such as toluene and chloroform.…”