Coumarin-doped PC/CdSSe/ZnS nanocomposite films: A reduced self-absorption effect for luminescent solar concentrators

Polymer-based Luminescent solar concentrators (LSCs) present a promising motivation to improve the response of photovoltaic cells towards diffuse solar radiation without the need for expensive sun tracking systems. The spectral overlap of the absorption and fluorescence spectra of the luminophores is one of the major problems that limit the optical efficiency of LSCs. This paper demonstrates a new nanocomposite for LSC host matrix based using Polycarbonate/CdSSe/ZnS nanocomposite films doped with a coumarin dyestuff as a basic luminophore. It was found that the photon trapping efficiency and Stokes' shift are improved by doping CdSSe/ZnS core/shell QDs into the polymeric matrix. The achieved values of fluorescence redshift and quantum yield were 97 nm and similar to 94% obtained for the doping concentration 0.3 wt% of QDs. The results were analyzed on the basis of the increase of the random-walk pathlength obtained by multiple scattering in addition to the synergistic fluorescence of coumarin dye and CdSSe/ZnS QDs.