Presentation Information
[25a-22B-5]Manipulating Exciton Recombination Toward Narrowband and High-Stability Organic Light-Emitting Diodes
〇(PC)Xun Tang1,2, Chihaya Adachi1,2,3 (1.Kyushu Univ., 2.Kyushu Univ., Dept. Appl. Chem., 3.Kyushu Univ., WPI-I2CNER)
Keywords:
Organic light-emitting diodes,Exciton manipulation,Device stability
Controlling the behaviors of charge carriers and excitons in organic light-emitting diodes (OLEDs) is crucial to achieving both high color purity and extended operational lifetime. Through a detailed transient electroluminescence (EL) analysis, the incorporation of a thermally activated delayed fluorescence (TADF) assistant molecule, possessing a deeply located lowest unoccupied molecular orbital (LUMO) energy level, effectively captures injected electrons within a bipolar host matrix. While maintaining the dominant role of host molecules in hole injection and transport, this alteration notably shifts the recombination zone towards the interface between the emissive layer and the electron-transporting layer (EML/ETL). Employing this bipolar host matrix as a non-barrier functional spacer between EML/ETL helps redistribute the recombination zone away from this interface, resulting in an optimized OLED that demonstrates a low driving voltage, promising device stability (LT95 > 400 hours, 95% of the initial luminance at 1000 cd m−2), and a high Commission Internationale de L’Éclairage (CIE)-y value approaching 0.70. In general. This work highlights the potential of managing excitons through precise energy level alignment to meet Rec.2020 standards while ensuring commercial-level stability.