Selective Passivation of Surface toward Bright Yellow Defective Emission of CdS Quantum Dots
Chao Wang1, Wen-Zhu Yang1, Zhi-Ming Feng1
1Key Laboratory of the Ministry of Education for Advanced Catalysis Material, Institute of Physical Chemistry, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, China.
Abstract:
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.
