Encapsulation of aggregation-caused quenching dye in metal-organic framework as emissive layer of organic light-emitting diodes

Abstract

Direct use of commercial luminescent dyes as an emissive layer for organic light-emitting diodes (OLEDs) has limitations due to aggregation-caused quenching (ACQ) effect of the dyes in solid state. Highly porous metal-organic frameworks (MOFs) have been employed as a host to prevent aggregation of dye molecules. A prototype Al-based MOF (MIL-100) was synthesized as a processable fluid gel and fabricated as thin film with sub-100 nm thickness for further encapsulation of ACQ dye. Luminescence of Coumarin 6 dye in MOF film was preserved in solid state with a quantum yield of 21.4%. The obtained composite film was directly used as an emissive layer for OLED fabrication. The device was turned on at low voltage of 4.4 V with the maximum electroluminescence and external quantum efficiency of 1.65 × 103 cd m−2 and 0.9%, respectively. This study shows the potential of using commercial ACQ dyes that are incorporated in porous platform as Emissive layer for OLED applications.