A highly efficient luminescent solar concentrator (LSC) composed of a nanosized metal-cluster as a molecular luminophore copolymerized with poly(methyl methacrylate) (PMMA) was fabricated through a simple solution process. Organic-inorganic salts such as (dMDAEMA)(2)[Mo6Cl14] and (dMDAEMA)(2)[Mo6I14] (where dMDAEMA is 2-(methacryloyloxy)ethyl dimethyldodecylammonium) were copolymerized with PMMA to generate a highly effective, transparent, and robust LSC waveguide. This hybrid luminophore enabled the development of a highly efficient UV-vis sunlight harvesting device due to strong absorption at UV-vis wavelengths up to similar to 500 nm and a large downshift of luminescence at near-infrared wavelengths (similar to 850 nm). Si photovoltaic c...