[TuP3H] H. Flexible materials

2:00 PM - 4:00 PM JST(5:00 AM - 7:00 AM UTC)

[TuP3H-10 LN] Enhanced Performance of Low-Voltage Organic Light-Emitting Diodes via an Upconversion Process Using Alkylated Soluble Fullerenes

〇Takuma Okaishi¹, Kazuki Kojima¹, Moeto Okuda¹, Takashi Kobayashi^1,2, Hiroyoshi Naito^2,3,4, Takashi Nagase^1,2 (1. Department of Physics and Electronics, Osaka Metropolitan Univ. (Japan), 2. The Res. Inst. for Molecular Electronic Devices (Japan), 3. Department of Applied Chemistry, Osaka Metropolitan Univ. (Japan), 4. Ritsumeikan Semiconductor Application Res. Center, Ritsumeikan Univ. (Japan))

In recent years, organic light-emitting diodes utilizing the upconversion process mediated by triplet-triplet annihilation have attracted increasing interest as a strategy for achieving low-voltage operation. Here, we demonstrate that aligned long alkyl chains of soluble fullerenes at the interface with rubrene layers effectively suppress both electroluminescence originating from the fullerene layer and the radiative recombination of charge-transfer excitons. Moreover, the turn-on voltage can be reduced by combining soluble fullerenes with different alkyl substituents. Furthermore, the introduction of dopants into the rubrene layer enables high luminance of approximately 6000 cd/m² at an applied voltage of 5 V.