High performance non-doped green organic light emitting diodes: Via delayed fluorescence

Sk, B and Thangaraji, V and Yadav, N and Nanda, GP and Das, S and Gandeepan, P and Zysman-Colman, E and Rajamalli, P (2021) High performance non-doped green organic light emitting diodes: Via delayed fluorescence. In: Journal of Materials Chemistry C, 9 (43). pp. 15583-15590.

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Abstract

Non-doped, delayed fluorescence organic light-emitting diodes (OLEDs) provide a route to high performance devices and simplified device fabrication. Here, two ambipolar anthracene derivatives containing a hole-transporting di-p-tolylamine and a carbazole and an electron-transporting phosphine oxide moiety are rationally designed and synthesized. The thermal and optoelectronic properties were investigated and the neat films of these compounds show high photoluminescence quantum yields of 84-87. Non-doped OLEDs with these luminogens exhibit green emission at �545 nm and an EQEmax of over 7.2 due to the delayed fluorescence resulting from triplet-triplet annihilation (TTA). The devices show a high luminance of over 104�400 cd m-2. Power efficiency and current efficiency maxima are up to 23.0 lm W-1 and 28.3 cd A-1, respectively. Moreover, the devices show very low efficiency roll-off and retain 90 of the maximum efficiency even at 20�000 cd m-2. When combined with a thermally activated delayed fluorescent (TADF) assistant dopant, the green-emitting OLEDs show a high EQEmax of 17.8. © The Royal Society of Chemistry.

Item Type:	Journal Article
Publication:	Journal of Materials Chemistry C
Publisher:	Royal Society of Chemistry
Additional Information:	The copyright for this article belongs to Royal Society of Chemistry
Keywords:	Doping (additives); Efficiency; Fluorescence; Luminance; Phosphorus compounds, Ambipolar; Anthracene derivatives; Delayed fluorescence; Device fabrications; Electron-transporting; Higher performance devices; Hole transporting; Non-doped; Performance; Phosphine oxide, Organic light emitting diodes (OLED)
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	21 Dec 2021 05:51
Last Modified:	21 Dec 2021 05:51
URI:	http://eprints.iisc.ac.in/id/eprint/70692

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