[15p-E402-1~18] 12.4 Organic light-emitting devices and organic transistors

▲ [15p-E402-7] Enhancing OLEDs Lifetime by Expanding CT Interface with TADF Assistant Dopant

〇(DC)Thanh Ba Nguyen¹, Hajime Nakanotani^1,2, Chihaya Adachi^1,2 (1.Kyushu Univ., 2.WPI I2-CNER2)

Keywords:OLED, Interface, Lifetime

In organic light-emitting diodes (OLEDs), there is a possibility for the generation of an emissive singlet exciton through a process called triplet-triplet upconversion (TTU), in which two electrically generated triplet excitons combine, resulting in a singlet exciton generation efficiency of up to 62.5%. Despite the underlying mechanism is still debated, TTU has been shown to occur efficiently at a charge-transfer (CT) interface due to the dense generation of triplet excitons at the interface. However, confining all charge carriers at such an interface greatly inhibits the operational stability of OLEDs due to processes such as polaron-exciton annihilation and molecular degradation at the interface. In this study, we propose a novel OLED design utilizing thermally activated delayed fluorescence (TADF) materials to expand the CT interface.