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.

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.

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%.

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.

Green organic light-emitting devices with external quantum efficiency up to nearly 30% based on an iridium complex with a tetraphenylimidodiphosphinate ligand

RSC Advances ◽  
2016 ◽  
Vol 6 (68) ◽  
pp. 63200-63205 ◽  
Author(s):  
Yanan Li ◽  
Liang Zhou ◽  
Yunlong Jiang ◽  
Rongzhen Cui ◽  
Xuesen Zhao ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
High Performance ◽  
Iridium Complex ◽  
Maximum Brightness ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light

High performance green electroluminescent device with maximum brightness, current efficiency, power efficiency and external quantum efficiency (EQE) up to 113 610 cd m−2, 112.30 cd A−1, 97.95 lm W−1 and 29.4%, was realized.

White OLEDs based on a novel EuIII-tetrakis-β-diketonate doped into 4,4′-N,N′-dicarbazolebiphenyl as emitting material

2015 ◽  
Vol 3 (22) ◽  
pp. 5775-5782 ◽  
Author(s):  
Silvanose Biju ◽  
Liang-Jin Xu ◽  
Cheng-Zhe Sun ◽  
Zhong-Ning Chen
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
Maximum Brightness ◽  
White Oleds

White OLEDs with an external quantum efficiency (EQE) of 2.8%, maximum brightness (L) of 1547 cd m−2, current efficiency (ηc) of 5.14 cd A−1 and power efficiency (ηp) of 2.53 lm W−1 were fabricated using a newly developed EuIII-tetrakis-β-diketonate compound.

Constructing host-σ-guest structures to optimize the efficiency of non-doped solution-processed OLEDs

2021 ◽  
Author(s):  
Dan Liu ◽  
Meng Zhang ◽  
Haowen Chen ◽  
Daiyu Ma ◽  
Wenwen Tian ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Power Efficiency ◽  
Blue Emission ◽  
Solution Processed

Non-doped solution-processed OLEDs based on emitters with host-σ-guest structures showed blue emission with CIE (0.18, 0.31), 24.9 cd A−1 current efficiency and 9.5 lm W−1 power efficiency.

Photoluminescence and electroluminescence of cationic PtAu2 heterotrinuclear complexes with aromatic acetylides

2017 ◽  
Vol 46 (3) ◽  
pp. 865-874 ◽  
Author(s):  
Li-Yi Zhang ◽  
Liang-Jin Xu ◽  
Jin-Yun Wang ◽  
Xian-Chong Zeng ◽  
Zhong-Ning Chen
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Solution Process ◽  
Heterometallic Complexes ◽  
Highly Efficient

Cationic PtAu2 heterometallic complexes are used as phosphorescent emitters for highly efficient electroluminescent OLEDs through a solution process with the highest current efficiency of 51.7 cd A−1 and external quantum efficiency of 14.5%.

Efficient electroluminescence of bluish green iridium complexes with 2-(3,5-bis(trifluoromethyl)phenyl)pyrimidine and 2-(3,5-bis(trifluoromethyl)phenyl)-5-fluoropyrimidine as the main ligands

2018 ◽  
Vol 5 (7) ◽  
pp. 1545-1552 ◽  
Author(s):  
Hua-Bo Han ◽  
Zheng-Guang Wu ◽  
You-Xuan Zheng
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Iridium Complexes ◽  
Bluish Green ◽  
Maximum Current

Four bluish green iridium complexes with high photoluminescence quantum efficiencies were applied in OLEDs, and they showed a maximum current efficiency of 74.70 cd A−1 and a maximum external quantum efficiency of 35.0% with mild efficiency roll-off.

Efficient bluish green electroluminescence of iridium complexes with good electron mobility

2018 ◽  
Vol 42 (16) ◽  
pp. 13351-13357 ◽  
Author(s):  
Hua-Bo Han ◽  
Zheng-Guang Wu ◽  
You-Xuan Zheng
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
Electron Mobility ◽  
External Quantum Efficiency ◽  
Iridium Complexes ◽  
Bluish Green ◽  
Maximum Current

Two efficient bluish green iridium complexes with good electron mobility were applied in efficient OLEDs, showing a maximum current efficiency of 71.18 cd A−1 and a maximum external quantum efficiency of 27.7%.

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