title: Dependence of luminescence efficiency of cdse quantum dots on chemical environments.
abstract: Dependence of photoluminescence (PL) efficiency (phiPL) of CdSe quantum dots (QDs) on coordinating solvents, precursors, and dispersing solvents was investigated. The phiPL of CdSe QDs was approximately 0.05 when synthesized at 120 degrees C using the precursors, cadmium acetate (CdAc) and trioctylphosphine selenide (TOPSe) in trioctylphosphine (TOP). The phiPL was increased from 0.05 to approximately 0.1 when coordinating solvents, trioctylphosphine oxide (TOPO) and hexadecylamine (HDA), were added to the above reaction mixture. The phiPL was dramatically increased from approximately 0.1 to appromixately 0.7 when CdAc was replaced by cadmium stearate (CdSt). The phiPL of CdSe QDs synthesized using cadmium stearate (CdSt)/TOPSe/TOP/TOPO was measured in butanol, chloroform, hexane, and toluene and found that the phiPL is strong dispersing solvent-dependent. The DFT analysis at b3lyp/lanl2dz level on the interaction of CdSe QDs with chemical environments showed that oxygen-containing molecules interact strongly with CdSe compared to non-oxygen containing molecules and could influence the phiPL.
authors.affiliation: NUS Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore-117576.
authors.forename: Rajan
authors.initials: R
authors.lastname: Jose
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Velmurugan
authors.initials: V
authors.lastname: Thavasi
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Baba
authors.forename: Seeram
authors.initials: S
authors.lastname: Ramakrishna
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D019187:Cadmium Compounds; D046911:Macromolecular Substances; D018036:Selenium Compounds; D012997:Solvents; C058667:cadmium selenide