New Phenanthro[9,10-d]oxazole-Based Fluorophores with Hybridized Local and Charge-Transfer Characteristics for Highly Efficient Blue Non-Doped OLEDs with Negligible Efficiency Roll-Off.

Autor: Xie DD; School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address., Liao HS; School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address., Wang BY; School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address., Chen D; School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address., Chi HJ; School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address., Lv YL; School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address., Dong Y; School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address., Li X; School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2024 May 28; Vol. 30 (30), pp. e202400121. Date of Electronic Publication: 2024 Apr 23.
DOI: 10.1002/chem.202400121
Abstrakt: It is vital to develop highly efficient non-doped blue organic light-emitting diodes (OLEDs) with high color purity and low-efficiency roll-off for applications in display and lighting. Herein, two blue D-A fluorophores TPA-PO and TPA-DPO are designed and synthesized, in which phenanthro[9,10-d]oxazole (PO) acts as the acceptor and triphenylamine as the donor. TPA-PO and TPA-DPO display good thermal stability and efficient luminescence efficiency in neat film. Results based on photophysical property and theoretical calculation demonstrate that TPA-PO and TPA-DPO possess the hybridized local and charge-transfer (HLCT) feature, which can utilize the triplet exciton to achieve highly efficient electroluminance (EL). The non-doped OLEDs with TPA-PO/TPA-DPO as pure emissive layer show the uniform EL emission peak at 468 nm, corresponding to CIE coordinates of (0.168, 0.187) and (0.167, 0.167), respectively. The TPA-DPO-based non-doped OLEDs provide the maximum external quantum efficiency (EQE) of 7.99 % and high exciton utility efficiency of 48.4 %~72.6 %. Moreover, the TPA-DPO-based device exhibits low-efficiency roll-off, still maintaining the EQE of 6.03 % at the high luminance of 5000 cd m -2 . Those findings state clearly that PO is a promising building block of blue fluorophore with a potential HLCT feature to be applied in non-doped OLEDs.
(© 2024 Wiley-VCH GmbH.)
Databáze: MEDLINE
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