Ligand-Induced Nucleation Growth Kinetics of CdTe QDs: Implications for White-Light-Emitting Diodes

Enhancements of the photoluminescence quantum yield (PL QY) and photochemical stability are critical factors for quantum dots (QDs) in the organic phase. In this article, we presented a flexible synthesis protocol for cadmium telluride (CdTe) QDs via controlling X-type ligands (3-methyl-benzoyl chloride), which simultaneously served as third-party initiators of the nucleation-growth process and surface ligand provider (Cl^–). The synthetic reaction was triggered at 100 °C, and the PL QY could reach up to 85%. It was discovered for the first time that the conversions between different sizes of magic-size clusters (MSCs) and QDs were sensitively induced by initiator stoichiometry. The obtained CdTe QDs possessed a zinc blende structure with a tetrahedral morphology and a narrow full width at half-maximum and covered the fluorescent window from 510 to 700 nm. The results showed that the CdTe QD surface was capped with resident oleylamine, thioalcohol, and a dynamically bound initiator (Cl^–). The prepared white-light-emitting diode (WLED) device based on CdTe QDs showed a high correlated color temperature (CCT), Ra, and CIE chromaticity coordinates of 5435 K, 93, and (0.334, 0.3498), respectively. This work will unlock the inspiration for the synthesis and application of other telluride QDs.