Optical Characterization of Laser ablated Copper/Copper Oxide Nanocomposites

Copper/copper oxide nanocomposites were prepared by laser ablation from a copper target in tetrahydrofuran with 0.0 wt% and 0.8 wt% concentrations of polystyrene. Ablation was performed with secondharmonic of pulsed nanosecond Nd:YAG laser (532 nm). The ultravioletvisible absorption spectra indicated two shoulders at 300 nm and 340 nm. The photoluminescence emission spectra (excited by 350 nm) displayed two broad range of peaks centered at 760 nm and 800 nm for the first measurement which confirmed the production of Cu/Cu2O nanocomposites. After 3 months, the photoluminescence emission spectra showed three peaks at 380, 400 nm and 420 nm. The obtained ultraviolet-visible absorption peaks and the photoluminescence emission spectra indicated the fabrication of Cu/Cu2O core-shell nanocomposites which during the time changed to Cu/CuO nanocomposites with more stable shells. We investigated on the size distribution and agglomeration of nanocomposites by transmission electron microscopy and dynamic light scattering, respectively. We observed a reduction in the average size of the nanocomposites from 50 nm to 30 nm by adding polymer (0.8 wt%) and increasing the pulse energy (from 80 mJ/pulse to 150 mJ/pulse). Moreover, the nanocomposites generated in the solution with polymer concentration showed less agglomeration.

Keywords:

Nanocomposites , Laser ablation , Pulse energy , Polymer concentration