Plasmonic thin-film luminescent solar concentrators (PTLSCs) were prepared by coating polycarbonate substrates with fluorescent PMMA films doped with coumarin dyes, nanogold and nanosilver molecules. The study of the absorption and fluorescence spectra showed a highly efficient light harvesting accompanied with metal enhanced fluorescence (MEF) of PTLSC films. The photostability measurements showed a decrease of the dye photodegradation rates by increasing nanogold concentration. The indoor testing of PTLSCs showed that the enhancement of the output power conversion efficiency was 53.2%, 33.4% and 25.8% obtained for a-Si and mc-Si and c-Si PV cells respectively. The field performance of PTLSCs under diffused radiation was evaluated by outdoor testing in Riyadh city (KSA) during winter and spring seasons, the study revealed that the maximum solar electrical conversion is well correlated to the solar irradiance type at the location.