| Abstract
| - The media used for dispersion have a significant effect on the photoluminescent (PL) efficiency ofcolloidal CdSe nanocrystals, in addition to synthetic parameters. The investigated dispersion media werewater-insoluble hexanes (Hex), toluene (Tol), chloroform (CHCl3), and water-miscible tetrahydrofuran(THF); in addition, a water−THF mixture (25%, weight), a tri-n-octylphosphine (TOP)−Hex mixture(25%, weight), and a TOP−THF mixture (25%, weight) were also explored as dispersion media. Solvent-dependent equilibriums affect the number of surface-adsorbed molecules available for surface passivationand the removal of surface ligands, with both concentration and additives (such as TOP) and time playinga role, so that PL intensities can either be enhanced or diminished depending on the detailed conditions.Moreover, an enhancement is not possible at low concentrations of nanocrystals after days of storage, asdissociation of the surface ligands plays a major role and leads to the formation of the other fluorescentspecies causing baseline uprising. The colloidal CdSe nanocrystals used were synthesized in a reactionmedium consisting of tri-n-octylphosphine (TOP), with cadium oxide (CdO) as the Cd precursor andTOPSe as the Se source.
- PL intensity is affected by dispersing environments and CdSe sample identity.
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