Jump to main content
Jump to site search


Benzimidazole–triazine based exciplex films as emitters and hosts to construct highly efficient OLEDs with a small efficiency roll-off

Author affiliations

Abstract

Although efficient exciplex-based organic light-emitting diodes (OLEDs) with simple device structures have shown great progress recently, highly efficient electron acceptor materials are still rare. Here, a series of newly developed electron acceptors for exciplex-OLEDs composed of benzimidazole and triazine hybrids are discussed. All three compounds display a triplet energy of 2.67–2.69 eV, ensuring a high photoluminescence quantum yield of 78.0–89.7% when mixed with an electron donor (TAPC: 4,4′-cyclohexylidenebis[N,N-bis(p-tolyl)aniline]). Exciplex-based OLEDs with these electron acceptors and TAPC blend films as the emitting layers exhibit low driving voltages of 2.6–3.0 V at 100 cd m−2 and 3.1–4.2 V at 1000 cd m−2. High efficiencies of 53.2–80.1 lm W−1 and 39.7–60.1 cd A−1 are obtained, and the highest external quantum efficiencies (EQE) are 12.5–18.4%. Green electro-phosphorescent emitters are also fabricated with exciplex-based cohosts by doping with tris(2-phenylpyridine)iridium (Ir(ppy)3), one of which shows the highest EQE of 29.6%, and the EQE can be maintained at 27.4% at 5000 cd m−2. Therefore, the benzimidazole–triazine electron acceptors show promise as exciplex emitters and cohosts for OLEDs.

Graphical abstract: Benzimidazole–triazine based exciplex films as emitters and hosts to construct highly efficient OLEDs with a small efficiency roll-off

Back to tab navigation

Supplementary files

Article information


Submitted
13 Nov 2019
Accepted
10 Jan 2020
First published
13 Jan 2020

J. Mater. Chem. C, 2020, Advance Article
Article type
Paper

Benzimidazole–triazine based exciplex films as emitters and hosts to construct highly efficient OLEDs with a small efficiency roll-off

B. Liang, J. Wang, Y. Cui, J. Wei and Y. Wang, J. Mater. Chem. C, 2020, Advance Article , DOI: 10.1039/C9TC06212B

Social activity

Search articles by author

Spotlight

Advertisements