Light-blue thermally activated delayed fluorescent emitters realizing a high external quantum efficiency of 25% and unprecedented low drive voltages in OLEDs

2016 ◽  
Vol 4 (12) ◽  
pp. 2274-2278 ◽  
Author(s):  
Ryutaro Komatsu ◽  
Hisahiro Sasabe ◽  
Yuki Seino ◽  
Kohei Nakao ◽  
Junji Kido
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
Blue Emission ◽  
Light Blue ◽  
Thermally Activated ◽  
Turn On

A series of TADF emitters composed of pyrimidine/acridine moieties are developed. The optimized device realized its highest power efficiency of 62 lm W−1, a high external quantum efficiency of 25%, and a low turn-on voltage of 2.8 V with light-blue emission.

Efficient phenanthroimidazole-styryl-triphenylamine derivatives for blue OLEDs: a combined experimental and theoretical study

2017 ◽  
Vol 41 (6) ◽  
pp. 2443-2457 ◽  
Author(s):  
Venugopal Thanikachalam ◽  
Elayaperumal Sarojpurani ◽  
Jayaraman Jayabharathi ◽  
Palanivel Jeeva
Keyword(s):  
Quantum Efficiency ◽  
Current Density ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
Theoretical Study ◽  
Blue Emission ◽  
Cie Coordinates

Blue emitting devices based on 2-(4′-9H-carbazol-9-yl)-[1,1′-styryl]-4-yl-1-benzylpiperidine-1H-phenanthro[9,10-d]imidazole (Cz-BPIS) exhibits blue emission with CIE coordinates of (0.16, 0.09), current density of 1.91 cd/A, power efficiency of 1.63 lm/W and external quantum efficiency of 2.61%.

scholarly journals Efficient fluorescent OLEDS based on assistant acceptor modulated HLCT emissive state for enhancing singlet exciton utilization

RSC Advances ◽  
2020 ◽  
Vol 10 (15) ◽  
pp. 8866-8879 ◽  
Author(s):  
Jayaraman Jayabharathi ◽  
Jagathratchagan Anudeebhana ◽  
Venugopal Thanikachalam ◽  
Sekar Sivaraj
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
Blue Emission ◽  
Singlet Exciton

OLED with C6/C9 substituted phenanthroimidazoles (DDPPPA/DDPBA) show blue emission with maximum external quantum efficiency (ηex), current efficiency (ηc) and power efficiency (ηp) of 5.7/6.0%, 10.5/12.0 cd A−1 and 8.3/9.2 lm W−1, respectively.

P-169: Light-Blue Thermally Activated Delayed Fluorescent Emitters Realizing a High External Quantum Efficiency of 25%

2016 ◽  
Vol 47 (1) ◽  
pp. 1754-1756
Author(s):  
Ryutaro Komatsu ◽  
Hisahiro Sasabe ◽  
Yuki Seino ◽  
Kohei Nakao ◽  
Junji Kido
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Blue ◽  
Thermally Activated

scholarly journals Asymmetrically twisted phenanthrimidazole derivatives as host materials for blue fluorescent, green and red phosphorescent OLEDs

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jayaraman Jayabharathi ◽  
Sekar Panimozhi ◽  
Venugopal Thanikachalam
Keyword(s):  
Energy Transfer ◽  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
Blue Emission ◽  
Deep Blue ◽  
Host Materials

AbstractThe electroluminescent properties of asymmetrically twisted phenanthrimidazole derivatives comprised of fluorescent anthracene or pyrene unit namely, 1-(1-(anthracen-10-yl)naphthalen-4-yl)-2-styryl-1H-phenanthro[9,10-d]imidazole (ANSPI), 1-(1-(pyren-1-yl) naphthalene-4-yl)-2-styryl-1H-phenanthro[9,10-d]imidazole (PNSPI), 4-(2-(4-(anthracen-9-yl) styryl)-1H-phenanthro[9,10-d]imidazol-1-yl)naphthalene-1-carbonitrile (ASPINC) and 4-(2-(4-(pyren-1-yl)styryl)-1H-phenanthro[9,10-d]imidazol-1-yl)naphthalene-1-carbonitrile (PSPINC) for blue OLEDs have been analyzed. The asymmetrically twisted conformation interrupt π-conjugation effectively results in deep-blue emission. The pyrene containing PSPINC based non-doped blue device (476 nm) shows maximium efficiencies (current efficiency (ηc)-4.23 cd/A; power efficiency (ηp)-2.86 lm/W; external quantum efficiency (ηex)-3.48%: CIE (0.16, 0.17) at 3.10 V. Among the doped blue devices, An(PPI)2:ASPINC shows high efficiencies (ηc-12.13 cd/A; ηp-5.98 lm/W; ηex-6.79%; L-23986 cd m−2; EL-458 nm) at 3.15 V with CIE (0.15, 0.17) than An(PPI)2:PSPINC based device which is inconsistent with non-doped device performances. The green and red PhOLEDs show higher efficiencies with Ir(ppy)3: ASPINC (ηc-50.6 cd/A; ηp-53.4 lm/W; ηex-17.0%; L-61581 cd m−2; EL-501 nm, CIE (0.31, 0.60) at 3.32 V and (bt)2Ir(dipba): ASPINC (ηc-15.2 cd/A; ηp-16.5 lm/W; ηex-14.5%; L-13456 cd m−2; EL-610 nm), CIE (0.63, 0.36) at 3.20 V, respectively. The complete energy transfer between the host and dopant molecules improved the efficiency of PHOLEDs.

scholarly journals Pyridinyl-Carbazole Fragments Containing Host Materials for Efficient Green and Blue Phosphorescent OLEDs

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4615
Author(s):  
Dovydas Blazevicius ◽  
Daiva Tavgeniene ◽  
Simona Sutkuviene ◽  
Ernestas Zaleckas ◽  
Ming-Ruei Jiang ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
Triplet Energy ◽  
New Host ◽  
High Brightness ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Host Materials

Pyridinyl-carbazole fragments containing low molar mass compounds as host derivatives H1 and H2 were synthesized, investigated, and used for the preparation of electro-phosphorescent organic light-emitting devices (PhOLEDs). The materials demonstrated high stability against thermal decomposition with the decomposition temperatures of 361–386 °C and were suitable for the preparation of thin amorphous and homogeneous layers with very high values of glass transition temperatures of 127–139 °C. It was determined that triplet energy values of the derivatives are, correspondingly, 2.82 eV for the derivative H1 and 2.81 eV for the host H2. The new derivatives were tested as hosts of emitting layers in blue, as well as in green phosphorescent OLEDs. The blue device with 15 wt.% of the iridium(III)[bis(4,6-difluorophenyl)-pyridinato-N,C2′]picolinate (FIrpic) emitter doping ratio in host material H2 exhibited the best overall characteristics with a power efficiency of 24.9 lm/W, a current efficiency of 23.9 cd/A, and high value of 10.3% of external quantum efficiency at 100 cd/m2. The most efficient green PhOLED with 10 wt% of Ir(ppy)3 {tris(2-phenylpyridine)iridium(III)} in the H2 host showed a power efficiency of 34.1 lm/W, current efficiency of 33.9 cd/A, and a high value of 9.4% for external quantum efficiency at a high brightness of 1000 cd/m2, which is required for lighting applications. These characteristics were obtained in non-optimized PhOLEDs under an ordinary laboratory atmosphere and could be improved in the optimization process. The results demonstrate that some of the new host materials are very promising components for the development of efficient phosphorescent devices.

Over 20% external quantum efficiency in red thermally activated delayed fluorescence organic light-emitting diodes using a reverse intersystem crossing activating host

2018 ◽  
Vol 6 (20) ◽  
pp. 5363-5368 ◽  
Author(s):  
Ji Han Kim ◽  
Dong Ryun Lee ◽  
Si Hyun Han ◽  
Jun Yeob Lee
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Intersystem Crossing ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light

Highly efficient red thermally activated delayed fluorescence organic light-emitting diodes were developed using a reverse intersystem crossing activating host derived from phenylcarbazole and pyridofuropyridine.

Efficient non-doped fluorescent OLEDs with nearly 6% external quantum efficiency and deep-blue emission approaching the blue standard enabled by quaterphenyl-based emitters

2018 ◽  
Vol 6 (16) ◽  
pp. 4479-4484 ◽  
Author(s):  
Weixuan Zeng ◽  
Yongbiao Zhao ◽  
Weimin Ning ◽  
Shaolong Gong ◽  
Zece Zhu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Blue Emission ◽  
Device Performance ◽  
Color Purity ◽  
Deep Blue ◽  
Blue Emitters ◽  
Excellent Color

Two quaterphenyl derivatives are rationally designed and synthesized as deep-blue emitters to simultaneously afford outstanding device performance and excellent color purity approaching the NTSC blue standard.

9,9-Diphenyl-thioxanthene derivatives as host materials for highly efficient blue phosphorescent organic light-emitting diodes

2015 ◽  
Vol 3 (38) ◽  
pp. 9999-10006 ◽  
Author(s):  
Kunkun Liu ◽  
Xiang-Long Li ◽  
Ming Liu ◽  
Dongcheng Chen ◽  
Xinyi Cai ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
Light Emitting Diodes ◽  
Maximum Power ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Host Materials ◽  
Blue Phosphorescent

A series of 9,9-diphenyl-9H-thioxanthene derivatives are reported as host materials in blue phosphorescent OLEDs, giving a maximum power efficiency of 69.7 lm W−1 and an external quantum efficiency of 29.0%.

High efficiency pure blue thermally activated delayed fluorescence molecules having 10H-phenoxaborin and acridan units

2015 ◽  
Vol 51 (46) ◽  
pp. 9443-9446 ◽  
Author(s):  
Masaki Numata ◽  
Takuma Yasuda ◽  
Chihaya Adachi
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Delayed Fluorescence ◽  
New Materials ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated

New materials emitting pure blue thermally activated delayed fluorescence achieve 20% external quantum efficiency and exhibit nearly concentration-independent photoluminescence.

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