Dependence of luminescence efficiency of CdSe quantum dots on chemical environments

Abstract

Dependence of photoluminescence (PL) efficiency (Φ PL) of CdSe quantum dots (QDs) on coordinating solvents, precursors, and dispersing solvents was investigated. The Φ PL of CdSe QDs was ∼0.05 when synthesized at 120 °C using the precursors, cadmium acetate (CdAc) and trioctylphosphine selenide (TOPSe) in trioctylphosphine (TOP). The Φ PL was increased from 0.05 to ∼0.1 when coordinating solvents, trioctylphosphine oxide (TOPO) and hexadecylamine (HDA), were added to the above reaction mixture. The Φ PL was dramatically increased from ∼0.1 to ∼0.7 when CdAc was replaced by cadmium stéarate (CdSt). The Φ PL of CdSe QDs synthesized using cadmium stéarate (CdSt)/TOPSe/TOP/TOPO was measured in butanol, chloroform, hexane, and toluene and found that the Φ PL 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 Φ PL. Copyright © 2008 American Scientific Publishers. All rights reserved.