Optical Stability of Thick-Shell CdSe@ZnS/ZnS Quantum Dots Dissolved in n-Octane in Wide Range of Mass Concentration: Photoluminescence Decay Study

Depending on the type of experiment, solid-state samples containing colloidal quantum dots (QDs) are prepared from solutions of radically different mass concentrations. The process of dilution of the base colloid, which is necessary for sample preparation, can lead to many undesirable effects, including significant deterioration of the optical properties of QDs. Herein, the stability of emission properties of thick-shell CdSe@ZnS/ZnS QDs dissolved in n-octane is investigated in a wide range of concentrations, from 15 to 0.01 mg mL(-1). The measurements of average exciton lifetime conducted as a function of the mass concentration clearly demonstrate that n-octane is a very stable solvent for such QDs, as it allows to keep the emission properties virtually unaffected by the process of even strong dilution.