High Efficiency over 15% by Breaking the Theoretical Efficiency Limit of Fluorescent Organic Light-Emitting Diodes with Localized Surface Plasmon Resonance Effects

The theoretical efficiency limit of fluorescence organiclight-emittingdiodes (OLEDs) was successfully surpassed by utilizing the localizedsurface plasmon resonance (LSPR) effect with conventional emissivematerials. The interaction between polaritons and plexcitons generatedduring the LSPR process was also analyzed experimentally. As a result,the external quantum efficiency (EQE) increased dramatically from6.01 to 15.43%, significantly exceeding the theoretical efficiencylimit of fluorescent OLEDs. Additionally, we introduced a new conceptof the LSPR effect, called "LSPR sensitizer", whichallowed for simultaneous improvement in color conversion and efficiencythrough cascade transfer of the LSPR effect. To the best of our knowledge,the EQE and the current efficiency of our LSPR-OLED are thehighest among LSPR-based fluorescent OLEDs to date.