Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (03): 653-659.doi: 10.3866/PKU.WHXB201212272

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

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

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