Exciplex-Based Electroluminescence: Over 21% External Quantum Efficiency and Approaching 100 lm/W Power Efficiency

Baoyan Liang; Jiaxuan Wang; Zong Cheng; Jinbei Wei; Yue Wang

doi:10.1021/acs.jpclett.9b01140

Exciplex-Based Electroluminescence: Over 21% External Quantum Efficiency and Approaching 100 lm/W Power Efficiency

J Phys Chem Lett. 2019 Jun 6;10(11):2811-2816. doi: 10.1021/acs.jpclett.9b01140. Epub 2019 May 15.

Authors

Baoyan Liang¹, Jiaxuan Wang¹, Zong Cheng¹, Jinbei Wei¹, Yue Wang¹

Affiliation

¹ State Key Laboratory of Supramolecular Structure and Materials , Jilin University , Changchun 130012 , People's Republic of China.

PMID: 31082247
DOI: 10.1021/acs.jpclett.9b01140

Abstract

Benzimidazole-triazine-based electron acceptor PIM-TRZ with high triplet exited-state energy and strong electron-transport ability was newly developed. A series of highly efficient exciplex emitters have been fabricated. The TAPC:PIM-TRZ (TAPC: di-[4-( N, N-ditoly amino)-phenyl]cyclohexane) film shows a high photoluminescence (PL) quantum yields (PLQY, Φ_f) of 93.4%, and the device based on TAPC:PIM-TRZ exhibits a low turn-on voltage of 2.3 V, high maximum efficiency of 71.2 cd A^-1 (current efficiency, CE), 97.3 lm W^-1 (power efficiency, PE), and 21.7% (external quantum efficiency, EQE), as well as a high EQE of 16.2% at a luminance of 5000 cd m^-2. The device displays the highest efficiency among reported organic light-emitting devices with an exciplex film as the emitting layer. Furthermore, a green device is also fabricated with a TAPC:PIM-TRZ cohost using C545T (C545T: (10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1 H,5 H,11 H-benzopyrano[6,7-8- I, j]quinolizin-11-one)) as the dopant, and the highest CE, PE, and EQE are 68.3 cd A^-1, 86.6 lm W^-1, and 20.2%, respectively.