High performance non-doped green organic light emitting diode via delayed fluorescence

P. G. thanks the Science & Engineering Research Board (SERB), India, for the Start-up Research Grant (SRG) (Grant No: SRG/2020/000161). E.Z-C. thanks the Engineering and Physical Sciences Research Council (EPSRC) EP/P010482/1 for support. P. R. thanks the Indian Institute of Science (IISc) for generous financial support and the Science & Engineering Research Board (SERB), India, for the SERB-Power Grant (SPG) (Grant No: SPG/2020/000107). B.S. thank IISc for the C. V. Raman Fellowship under the Institute of Eminence (IoE).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%.PostprintPeer reviewe

Ultrathin non-doped thermally activated delayed fluorescence emitting layer for highly efficient OLEDs

We report highly efficient, ultrathin non-doped green and bluish-green organic light-emitting diodes (OLEDs) using a thermally activated delayed fluorescence (TADF) emitter. The green OLED with an ultrathin (~1 nm) EML showed a 2.6-fold higher external quantum efficiency (EQEmax) of 13.5% with a luminance of 17,250cd/m-2 than the conventional (30 nm) non-doped device

Ultrathin non-doped thermally activated delayed fluorescence emitting layer for highly efficient OLEDs

The authors are grateful to Prof. Chien-Hong Cheng, National Tsing Hua University, Taiwan for providing facilities for OLED device fabrication and characterization. G.P.N. thanks Council of Scientific & Industrial Research (CSIR) India for the Junior Research Fellowship (JRF). E.Z-C. thanks the Engineering and Physical Sciences Research Council (EPSRC) EP/P010482/1 for support. E. Z.-C. is a Royal Society Leverhulme Trust Senior Research fellow (SRF\R1\201089). P. R. thanks the Indian Institute of Science (IISc) for generous financial support and the Science & Engineering Research Board (SERB), India, for the SERB-Power Grant (SPG) (Grant No: SPG/2020/000107). BS thank IISc for the C. V. Raman Fellowship under the Institute of Eminence (IoE).We report highly efficient, ultrathin non-doped green and bluish-green organic light-emitting diodes (OLEDs) using a thermally activated delayed fluorescence (TADF) emitter. The green OLED with an ultrathin (~1 nm) EML showed a 2.6-fold higher external quantum efficiency (EQEmax) of 13.5% with a luminance of 17,250 cd/m2 than the conventional (30 nm) non-doped device.PostprintPeer reviewe

CCDC 1580567: Experimental Crystal Structure Determination

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