Electrospun nanofibers with dual plasmonic-enhanced luminescent solar concentrator effects for high-performance organic photovoltaic cells

We fabricated dual functional electrospun (ES) nanofibers by a coaxial electrospinning technique for enhancing the organic photovoltaic (OPV) device efficiency. The nanofibers contained poly[2,7-(9,9-dihexylfluorene)-alt-4,7-(2,1,3-benzothiadiazole)] (PFBT) nanoparticles as the luminescent solar concentrator (LSC) and Ag nanoparticles for the surface plasmon resonance (SPR) effect. Aligned- and crossed-fiber architecture patterns were fabricated to compare the effects of the architecture on the OPV efficiency. The plasmonic-enhanced LSC ES nanofibers with crosslinked poly(methacrylic acid) could be directly integrated into the conventional OPV configuration without sacrificing the coverage area of the active layer. In addition, the in situ reduction of Ag nanoparticles simultaneously enhanced the exciton generation of PFBT and the active materials with the SPR effect. The dual functional ES nanofibers with a crossed-pattern embedded into OPV devices provided significant light harvesting through down conversion and enhanced exciton generation. They led to PCE values of 4.11 and 7.12% for P3HT (poly(3-hexylthiophene)) :PC₆₁BM ([6,6]-phenyl C₆₁-butyric acid methyl ester) and PTB7 (polythieno[3,4-b]-thiophene-co-benzodithiophene) :PC₇₁BM ([6,6]-phenyl C₇₁-butyric acid methyl ester) ([6,6]-phenyl) photovoltaic cells, respectively, which are 18% enhancements compared to their parent devices. This interface-modification approach using plasmonic-enhanced LSC ES nanofibers provides a new approach for enhancing the OPV device performance.