Highly efficient and rapid green synthesis of CdSe quantum dots with precise size control and well-defined optical behavior

In this study, high quality CdSe quantum dots (QDs) were prepared by a rapid and eco-friendly phosphine-free method using paraffin oil as low-cost non-coordinating solvent and oleic acid as a capping ligand thus eliminating the need of toxic and expensive coordinating solvents such as trioctylphosphine (TOP) or tributylphosphine (TBP). XRD analysis confirmed the formation of zinc-blend phase with crystallite size of 10.80 – 12.35 nm. The characteristic red-shift in both absorption and emission spectra was observed with increasing reaction time due to augmented QDs sizes. PL measurements revealed that the QDs exhibited a narrow photoluminescence full width at half maximum (FWHM) of approximately 21-23 nm, demonstrating excellent optical purity, minimal defect-related emission, and high colloidal stability. Effective core radii estimated by the Effective Mass Approximation and Hyperbolic Band Model ranging from 6.4 to 7.2 nm evidenced strong quantum confinement effects.