Selective Passivation of Surface toward Bright Yellow Defective Emission of CdS Quantum Dots

CdE (E = S, Se) quantum dots (QDs) with a broad and large Stokes shift PL emission have emerged as potential materials for white-light LEDs. However, this surface-related emission of nanocrystals is currently limited by low quantum efficiency. Herein, a convenient noninjected one-pot method at a relatively low temperature to prepare CdS QDs was readily achieved. The CdS-368 QD displays intense broad yellow emission in both solution and the solid state at room temperature. The coligation of organic and inorganic ligands passivates the electron trap states at the QD surface and suppresses nonradiative recombination, which is responsible for the high stability of colloids in organic solvents and the distinct fluorescence quantum yield.

Automated summary

CdE (E = S, Se) quantum dots (QDs) with broad and large Stokes shift PL emission have potential applications in white-light LEDs. However, the current limitation is the low quantum efficiency of the surface-related emission of nanocrystals. In this study, a convenient non-injected one-pot method at a relatively low temperature was used to prepare CdS QDs. The CdS-368 QD exhibits intense broad yellow emission in solution and the solid state at room temperature. The coligation of organic and inorganic ligands passivates the electron trap states at the QD surface, leading to high stability of colloids in organic solvents and an enhanced fluorescence quantum yield.