Synthesis and Optical Properties of Thiol Functionalized CdSe/ZnS (Core/Shell) Quantum Dots by Ligand Exchange
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); South China Univ. of Technology (SCUT), Gangzhou (China)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Beijing Univ. of Chemical Technology (China)
- National Research Council of Canada, Ottawa, ON (Canada)
- South China University of Technology, Guangzhou, PR China
The colloidal photoluminescent quantum dots (QDs) of CdSe (core) and CdSe/ZnS (core/shell) were synthesized at different temperatures with different growth periods. The optical properties (i.e., UV/Vis spectra and photoluminescent emission spectra) of the resulting QDs were investigated. The CdSe/ZnS QDs exhibited higher photoluminescent (PL) efficiency and stability than their corresponding CdSe core QDs. Ligand exchange with various thiol molecules was performed to replace the initial surface passivation ligands, that is, trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP), and the optical properties of the surface-modified QDs were studied. The thiol ligand molecules used included 1,4-benzenedimethanethiol, 1,16-hexadecanedithiol, 1,11-undecanedithiol, 11-mercapto-1-undecanol, and 1,8 octanedithiol. After the thiol functionalization, the CdSe/ZnS QDs exhibited significantly enhanced PL efficiency and storage stability. Besides surface passivation effect, such enhanced performance of thiol-functionalized QDs could be due to self-assembly formation of dimer/trimer clusters, in which QDs are linked by dithiol molecules. Effects of ligand concentration, type of ligand, and heating on the thiol stabilization of QDs were also discussed.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Temperature Materials Lab. (HTML)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1124501
- Journal Information:
- Journal of Nanomaterials, Vol. 2014, Issue ID324972; ISSN 1687-4110
- Publisher:
- Hindawi
- Country of Publication:
- United States
- Language:
- English
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