High-performance blue OLED using multiresonance thermally activated delayed fluorescence host materials containing silicon atoms

• Published in: Nature communications Vol. 14; no. 1; pp. 5589 - 9
• Main Authors: Park, Dongmin, Kang, Seokwoo, Ryoo, Chi Hyun, Jhun, Byung Hak, Jung, Seyoung, Le, Thi Na, Suh, Min Chul, Lee, Jaehyun, Jun, Mi Eun, Chu, Changwoong, Park, Jongwook, Park, Soo Young
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11-09-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 132/122; 140/131; 140/58; 147/3; 639/624/1020/1091; 639/638/298/398; Anthracene; Diamines; Dopants; Efficiency; Emitters; Energy transfer; Fluorescence; Horizontal orientation; Humanities and Social Sciences; Luminescence; multidisciplinary; Organic light emitting diodes; Photoluminescence; Photons; Quantum efficiency; Science; Science (multidisciplinary); Silicon; Thermal stability
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-41440-1

We report three highly efficient multiresonance thermally activated delayed fluorescence blue-emitter host materials that include 5,9-dioxa-13b-boranaphtho[3,2,1-
de
]anthracene (DOBNA) and tetraphenylsilyl groups. The host materials doped with the conventional
N
7
,
N
7
,
N
13
,
N
13
,5,9,11,15-octaphenyl-5,9,11,15-tetrahydro-5,9,11,15-tetraaza-19b,20b-diboradinaphtho[3,2,1-
de
:1’,2’,3’-
jk
]pentacene-7,13-diamine (
ν
-DABNA) blue emitter exhibit a high photoluminescence quantum yield greater than 0.82, a high horizontal orientation greater than 88%, and a short photoluminescence decay time of 0.96–1.93 μs. Among devices fabricated using six synthesized compounds, the device with (4-(2,12-di-
tert
-butyl-5,9-dioxa-13
b
-boranaphtho[3,2,1-
de
]anthracen-7-yl)phenyl)triphenylsilane (TDBA-Si) shows high external quantum efficiency values of 36.2/35.0/31.3% at maximum luminance/500 cd m
−2
/1,000 cd m
−2
. This high performance is attributed to fast energy transfer from the host to the dopant. Other factors possibly contributing to the high performance are a T
1
excited-state contribution, inhibition of aggregation by the bulky tetraphenylsilyl groups, high horizontal orientation, and high thermal stability. We achieve a high efficiency greater than 30% and a small roll-off value of 4.9% at 1,000 cd m
−2
using the TDBA-Si host material.
Effective energy transfer and suppressed dopant aggregation is critical for realizing efficient organic light-emitting diodes. Here, the authors report six host materials capable of exhibiting enhanced thermal stability and film-formation behavior, demonstrating efficiency of over 30% at 1000 cd/m
2
.