Preparation of Crystalline Gold Nanoparticles and Their Prospects in Enhancement of Solar Energy Conversion Efficiency.

Crystalline gold nanoparticles of about 78 nm were synthesized and embedded with different concentrations in fluorescent polymer to form fluorescent polymer nanocomposite films. The fluorescent polymer was polymethylmethacrylate (PMMA) doped with a coumarin dyestuff. Both of the prepared gold nanoparticles and nanocomposite polymer films were characterized using X-ray diffraction, UV-vis absorption spectroscopy and fluorescence spectroscopy. A maximum enhancement of the dye fluorescence was observed for a concentration about 20 ppm for gold nanoparticles. The fluorescence characteristics (fluorescence peak , quantum yield and the spectral narrowing), were found to be strongly dependent on the concentration of gold nanoparticles. Our results demonstrated that the maximum fluorescence enhancement can be obtained when the incident light and fluorescence light are in optimum resonance with the surface plasmons in gold nanoparticles. The effect of temperature and UV radiation on the surface plasmon absorption recommended their promising weathering durability for using in various solar energy applications.King Saud Universit