物理化学学报 >> 2013, Vol. 29 >> Issue (03): 653-659.doi: 10.3866/PKU.WHXB201212272

材料物理化学 上一篇    下一篇

硫脲修饰ZnSe:Cu量子点的水相合成及荧光特性

汤子龙, 李冬梅, 程经纬, 蒋洁如   

  1. 上海大学材料科学与工程学院, 上海 200072
  • 收稿日期:2012-11-01 修回日期:2012-12-26 发布日期:2013-02-25
  • 通讯作者: 李冬梅 E-mail:dmli@mail.shu.edu.cn

Preparation and Fluorescence Properties of Aqueous Soluble Thiourea Modified ZnSe:Cu Quantum Dots

TANG Zi-Long, LI Dong-Mei, CHENG Jing-Wei, JIANG Jie-Ru   

  1. College of Materials Science and Engineering, Shanghai University, Shanghai 200072, P.R. China
  • Received:2012-11-01 Revised:2012-12-26 Published:2013-02-25

摘要:

以3-巯基丙酸为稳定剂在水相中合成了Cu掺杂的ZnSe量子点(QDs), 并利用硫脲(CH4N2S)对其进行表面修饰, 制备出核壳结构的ZnSe:Cu/ZnS 量子点. 制得的量子点呈闪锌矿结构, 尺寸约为5 nm, 有较好的分散性, 其荧光发射峰在460 nm左右. 经CH4N2S修饰后, 量子点表面形成了宽禁带的ZnS包覆层, 将电子和空穴限域在了ZnSe:Cu 核内, 减少了表面发生非辐射复合的载流子, 显著提高了量子点的荧光强度. 与Na2S、硫代乙酰胺(TAA)等常用硫源相比, 以CH4N2S为硫源制得的ZnSe:Cu/ZnS 量子点壳层厚度可控, 表面钝化效果更好, 显示出更佳的荧光效率和稳定性. ZnSe:Cu/ZnS 量子点经过紫外线照射后消除了表面的悬空键, 进一步提高了其量子产率, 最终获到了具有较好荧光性质的ZnSe:Cu/ZnS量子点.

关键词: 量子点, ZnSe:Cu/ZnS, 水相合成, 硫脲修饰, 低毒性, 紫外光照

Abstract:

Aqueous phase Cu doped ZnSe (ZnSe:Cu) quantum dots (QDs) stabilized with mercaptopropionic acid were prepared, and thiourea was used as a surface modifier to obtain core-shell ZnSe:Cu/ZnS QDs. QDs had a sphalerite structure, were uniformly dispersed, had an average particle size of approximately 5 nm and an emission peak at around 460 nm. After thiourea modification, a wide band-gap ZnS shell was coated on the QDs to passivate the surface, reduce surface states, and significantly improve fluorescence intensity. Thiourea modified ZnSe:Cu/ZnS QDs exhibit better surface passivation, fluorescence efficiency, and stability than those of other surface modifiers like Na2S and thioacetamide. Quantum yields were further improved after UV irradiation eliminated surface dangling bonds.

Key words: Quantum dot, ZnSe:Cu/ZnS, Aqueous phase synthesis, Thiourea modified, Low toxicity, UV irradiation

MSC2000: 

  • O644