Synthesis and Laser Immobilization onto Solid Substrates of CdSe/ZnS Core Shell Quantum Dots

CdSe/ZnS core-shell quantum dots (QDs) have been immobilized by ultraviolet matrix-assisted pulsed laser evaporation (UV-MAPLE) onto SiO2 glass substrates covered by silica thin films. The silica thin films were deposited by the sol-gel method. An UV KrF* (lambda = 248 nm, tau(fwhm) congruent to 25 ns) excimer laser source was used for the laser immobilization experiments. Toluene was chosen as solvent material for the preparation of the composite MAPLE targets. The surface morphology and growth mode of the deposited structures were investigated by optical and atomic force microscopy in acoustic (dynamic) configuration. The crystalline structure and chemical composition of the base material used for the preparation of the MAPLE targets as well as the laser transferred QDs were studied by transmission electron microscopy and energy dispersive X-ray spectroscopy. The functional properties of the immobilized QDs were studied by fluorescence microscopy. The immobilized materials form self-organized 2D arrays constituted by complex CdSe/ZnS core-shell QDs preserving the functional properties of the base material used for the preparation of the MAPLE targets.