Highly efficient and well-resolved Mn²⁺ ion emission in MnS/ZnS/CdS quantum dots

作者：Cao, Sheng^*; Zheng, Jinju; Zhao, Jialong; Wang, Lin; Gao, Fengmei; Wei, Guodong; Zeng, Ruosheng; Tian, Linhai; Yang, Weiyou

来源：Journal of Materials Chemistry C, 2013, 1(14): 2540-2547.

DOI：10.1039/c3tc00561e

• CDS/ZNS CORE/SHELL NANOCRYSTALS
• MN2+-DOPED CDS NANOCRYSTALS
• DOPED ZNSE NANOCRYSTALS
• SEMICONDUCTOR NANOCRYSTALS
• SURFACE
• LIGHT
• PHOTOLUMINESCENCE
• LUMINESCENCE
• DYNAMICS
• EMITTERS

We demonstrate a strategy for the growth of Mn2+ ion doped cadmium based II-VI semiconductor quantum dots (QDs) with a designed buffer layer of ZnS (MnS/ZnS/CdS or Mn:CdS QDs), which aims to meet the challenge of obtaining highly efficient and well-resolved Mn2+ ion emission. First, small, high quality MnS cores are obtained by using thiols to replace conventional alkyl amines as capping ligands. Then a buffer layer of ZnS with a tailored thickness is introduced to the QDs before the growth of CdS shells to reduce the size mismatch between the Mn2+ (dopant) and Cd2+ (host) ions. The fabricated MnS/ZnS/CdS core/shell QDs exhibit a high PL QY of up to 68%, which is the highest ever reported for any type of Mn2+ ion doped cadmium based II-VI semiconductor QD. The photoluminescence (PL) of the QDs consists of well-resolved Mn2+ ion emission without any detectable emission from the CdS band edge or surface defects. In addition, our MnS/ZnS/CdS QDs cannot only be made water-soluble, but can also be coated by ligands with short carbon chain lengths, nearly without cost to the PL QY, which could make them strong candidates for practical applications in biology/biomedicine and opto/electronic devices.

• 单位
  贵州师范大学; 中国科学院长春光学精密机械与物理研究所; 太原理工大学; 宁波工程学院; 发光学及应用国家重点实验室