Plasmonic luminescent down shifting layers for the enhancement of CdTe mini-modules performance

In this investigation, plasmonic coupling between luminescent species (lumogen yellow, and silver nanoparticles (Ag NPs) has been exploited to produce significant enhancement in absorption and fluorescence emission of lumogen yellow dye luminescent downshifting (LDS) layers. The optimum dye concentration in a poly(methyl,methacrylate) polymer LDS layer of ∼100 μm thickness was established. Subsequently, plasmonic coupling with Ag NPs was introduced and optimum concentration has been determined for the composite plasmonic Luminescent Down-Shifting (pLDS) layers. The optimum plasmonic coupling has been observed to produce fluorescence emission enhancement of up to 81% for the dye-pLDS layers. The pLDS layers were deposited on top of CdTe mini-modules to investigate the action of plasmonic interaction in LDS layers. It has been demonstrated that the addition of pLDS layers containing lumogen yellow dye increases the short circuit current density (Jsc) of CdTe devices between 300 and 500 nm. An increase of ∼100% has been achieved. External quantum efficiency (EQE) measurements of the pLDS layers have also shown significant improvement below 500 nm reaching 25-40%, while increased efficiency was confirmed with current-voltage (J-V) measurements.