High Efficiency Green Fluorescent Dopant Through the Optimized Side Group for Organic Light Emitting Diodes

2021 ◽  
Vol 21 (7) ◽  
pp. 4000-4004
Author(s):  
Hyukmin Kwon ◽  
Seokwoo Kang ◽  
Sangshin Park ◽  
Sunwoo Park ◽  
Seungeun Lee ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Green Light ◽  
Molecular Size ◽  
Electrical Energy ◽  
Light Emitting ◽  
Tert Butyl ◽  
Green Fluorescent

OLED light emitting materials have a molecular size corresponding to the nano scale and are converted into light energy when given electrical energy. The new green fluorescent dopant material was successfully synthesized by using anthracene as a central core and introducing a methyl group and tert-butyl group at various positions as diphenylamine group. Two compounds are N9,N9,N10,N10-tetraphenylanthracene-9,10-diamine (TAD) and N9,N10-bis(4-(tert-butyl) phenyl)-N9,N10-di-o-tolylanthracene-9,10-diamine (p-Tb-o-Me-TAD). The synthesized material emits green light with the maximum wavelengths of 508 and 523 nm. p-Tb-o-Me-TAD shows excellent PLQY of 86.2% in solution state. When the synthesized material was used as a dopant in a device, TAD showed current efficiency (CE) of 17.71 cd/A and external quantum efficiency (EQE) of 6.11%. The device using p-Tb-o-Me-TAD dopant exhibited current efficiency (CE) of 24.24 cd/A and external quantum efficiency (EQE) of 7.27%.

Synthesis and Electroluminescence Property of Anthracene Green Fluorescent Derivatives Based on Optimized Side Groups

2021 ◽  
Vol 21 (7) ◽  
pp. 4037-4041
Author(s):  
Sangshin Park ◽  
Hyukmin Kwon ◽  
Seokwoo Kang ◽  
Sunwoo Park ◽  
Hyocheol Jung ◽  
...  
Keyword(s):  
Electric Field ◽  
Energy Conversion ◽  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Molecular Size ◽  
Green Fluorescent ◽  
Fluorescent Derivatives ◽  
Electroluminescence Property

Molecular size of OLED emitting materials is nano-metric size and when it is applied to the electric field it emits the light based on the energy conversion result. As new green fluorescent emitters, N,N,N',N'-Tetra-m-tolyl-anthracene-9,10-diamine (m-Me-TAD) and N,N,N',N'-Tetra-p-tolyl-anthracene-9,10-diamine (p-Me-TAD) were synthesized and the properties were evaluated. In solution state, photoluminescence (PL) maximum wavelength is 517 nm for m-Me-TAD and 529 nm for p-Me-TAD. In electroluminescence (EL) spectra, EL maximum wavelength of m-Me-TAD is 518 nm and p-Me-TAD is 533 nm. The doped device using m-Me-TAD as green fluorescent dopant exhibited current efficiency (CE) of 17.41 cd/A and external quantum efficiency (EQE) of 7.41%. The doped device with p-Me-TAD was optimized in order to achieve a green OLED with high efficiency.

High-efficiency organic light-emitting diodes of phosphorescent PtAg2heterotrinuclear acetylide complexes supported by triphosphine

2017 ◽  
Vol 5 (12) ◽  
pp. 3072-3078 ◽  
Author(s):  
Yi-Peng Li ◽  
Xin-Xia Fan ◽  
Yue Wu ◽  
Xian-Chong Zeng ◽  
Jin-Yun Wang ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Heterometallic Cluster ◽  
Organic Light ◽  
New Type ◽  
Heterometallic Cluster Complexes

Platinum(ii)–silver(i) heterometallic cluster complexes are used as a new type of phosphorescent dopant to achieve high-efficiency OLEDs with 67.4 cd A−1peak current efficiency (CE) and 17.4% external quantum efficiency (EQE).

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.

scholarly journals Record High External Quantum Efficiency of 19.2% Achieved in Light-Emitting Diodes of Colloidal Quantum Wells Enabled by Hot-Injection Shell Growth

2019 ◽  
Author(s):  
Baiquan Liu ◽  
Yemliha Altintas ◽  
Lin Wang ◽  
Sushant Shendre ◽  
Manoj Sharma ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Shell Growth ◽  
Light Emitting ◽  
Hot Injection ◽  
Key Factor

<p> Colloidal quantum wells (CQWs) are regarded as a new, highly promising class of optoelectronic materials thanks to their unique excitonic characteristics of high extinction coefficient and ultranarrow emission bandwidth. Although the exploration of CQWs in light-emitting diodes (LEDs) is impressive, the performance of CQW-LEDs lags far behind compared with other types of LEDs (e.g., organic LEDs, colloidal quantum-dot LEDs, and perovskite LEDs). Herein, for the first time, the authors show high-efficiency CQW-LEDs reaching close to the theoretical limit. A key factor for this high performance is the exploitation of hot-injection shell (HIS) growth of CQWs, which enables a near-unity photoluminescence quantum yield (PLQY), reduces nonradiative channels, ensures smooth films and enhances the stability. Remarkably, the PLQY remains 95% in solution and 87% in film despite rigorous cleaning. Through systematically understanding their shape-, composition- and device- engineering, the CQW-LEDs using CdSe/Cd<sub>0.25</sub>Zn<sub>0.75</sub>S core/HIS CQWs exhibit a maximum external quantum efficiency of 19.2%. Additionally, a high luminance of 23,490 cd m<sup>-2</sup>, extremely saturated red color with the Commission Internationale de L’Eclairage coordinates of (0.715, 0.283) and stable emission are obtained. The findings indicate that HIS grown CQWs enable high-performance solution-processed LEDs, which may pave the path for CQW-based display and lighting technologies.</p>

High-efficiency, deep blue ZnCdS/CdxZn1−xS/ZnS quantum-dot-light-emitting devices with an EQE exceeding 18%

Nanoscale ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 5650-5657 ◽  
Author(s):  
Ouyang Wang ◽  
Lei Wang ◽  
Zhaohan Li ◽  
Qiulei Xu ◽  
Qingli Lin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Deep Blue

18% peak external quantum efficiency (EQE) for deep blue QLEDs by using ZnCdS/CdxZn1−xS/ZnS quantum dots.

Green fluorescent organic light-emitting device with external quantum efficiency of nearly 10%

2006 ◽  
Vol 89 (6) ◽  
pp. 063504 ◽  
Author(s):  
Kenji Okumoto ◽  
Hiroshi Kanno ◽  
Yuji Hamaa ◽  
Hisakazu Takahashi ◽  
Kenichi Shibata
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting ◽  
Organic Light ◽  
Green Fluorescent

scholarly journals Record High External Quantum Efficiency of 19.2% Achieved in Light-Emitting Diodes of Colloidal Quantum Wells Enabled by Hot-Injection Shell Growth

2019 ◽  
Author(s):  
Baiquan Liu ◽  
Yemliha Altintas ◽  
Lin Wang ◽  
Sushant Shendre ◽  
Manoj Sharma ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Shell Growth ◽  
Light Emitting ◽  
Hot Injection ◽  
Key Factor

<p> Colloidal quantum wells (CQWs) are regarded as a new, highly promising class of optoelectronic materials thanks to their unique excitonic characteristics of high extinction coefficient and ultranarrow emission bandwidth. Although the exploration of CQWs in light-emitting diodes (LEDs) is impressive, the performance of CQW-LEDs lags far behind compared with other types of LEDs (e.g., organic LEDs, colloidal quantum-dot LEDs, and perovskite LEDs). Herein, for the first time, the authors show high-efficiency CQW-LEDs reaching close to the theoretical limit. A key factor for this high performance is the exploitation of hot-injection shell (HIS) growth of CQWs, which enables a near-unity photoluminescence quantum yield (PLQY), reduces nonradiative channels, ensures smooth films and enhances the stability. Remarkably, the PLQY remains 95% in solution and 87% in film despite rigorous cleaning. Through systematically understanding their shape-, composition- and device- engineering, the CQW-LEDs using CdSe/Cd<sub>0.25</sub>Zn<sub>0.75</sub>S core/HIS CQWs exhibit a maximum external quantum efficiency of 19.2%. Additionally, a high luminance of 23,490 cd m<sup>-2</sup>, extremely saturated red color with the Commission Internationale de L’Eclairage coordinates of (0.715, 0.283) and stable emission are obtained. The findings indicate that HIS grown CQWs enable high-performance solution-processed LEDs, which may pave the path for CQW-based display and lighting technologies.</p>

High-efficiency quantum dot light-emitting diodes employing lithium salt doped poly(9-vinlycarbazole) as a hole-transporting layer

2017 ◽  
Vol 5 (22) ◽  
pp. 5372-5377 ◽  
Author(s):  
Ying-Li Shi ◽  
Feng Liang ◽  
Yun Hu ◽  
Xue-Dong Wang ◽  
Zhao-Kui Wang ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Lithium Salt ◽  
Light Emitting ◽  
Hole Transporting

The maximum external quantum efficiency of the device is 11.46% using PVK doped Li-TFSI as the hole-transporting layer.

Non-halogenated solvent-processed highly efficient green Ir(iii) complexes with an external quantum efficiency exceeding 23% for phosphorescent organic light-emitting diodes

2020 ◽  
Vol 8 (37) ◽  
pp. 12959-12967
Author(s):  
Raja Kumaresan ◽  
Athithan Maheshwaran ◽  
Ho-Yeol Park ◽  
Kyungmin Sung ◽  
Jungmin Choi ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Highly Efficient ◽  
Organic Light

High efficiency green phosphorescent Ir(III) complexes with solubilizing groups introduced to enable non-halogenated solvent-based fabrication of PHOLEDs with high EQE and CE values.

High Efficiency Light Emission Devices in Silicon

2003 ◽  
Vol 770 ◽  
Author(s):  
Maria E. Castagna ◽  
Salvatore Coffa ◽  
Mariantonietta Monaco ◽  
Anna Muscara' ◽  
Liliana Caristia ◽  
...  
Keyword(s):  
Rare Earth ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Gate Dielectric ◽  
Chemical Vapour ◽  
Rare Earth Ions ◽  
Hot Electrons ◽  
Light Emitting ◽  
The Rare Earth

AbstractWe report on the fabrication and performances of the most efficient Si-based light sources. The devices consist of MOS structures with erbium (Er) implanted in the thin gate oxide. The devices exhibit strong 1.54 μm electroluminescence at 300K with a 10% external quantum efficiency, comparable to that of standard light emitting diodes using III-V semiconductors. Emission at different wavelenghts has been achieved incorporating different rare earths (Ce, Tb, Yb, Pr) in the gate dielectric. The external quantum efficiency depends on the rare earth ions incorporated and ranges from 10% (for an Tb doped MOS) to 0.1% (for an Yb doped MOS). RE excitation is caused by hot electrons impact and oxide wearout limits the reliability of the devices. Much more stable light emitting MOS devices have been fabricated using Er-doped SRO (Silicon Rich Oxide) films as gate dielectric. These devices show a high stability, with an external quantum efficiency reduced to 0.2%. In these devices Er pumping occurs part by hot electrons and part by energy transfer from the Si nanostructures to the rare earth ions, depending by Si excess in the film. Si/SiO2 Fabry-Perot microcavities have been fabricated to enhance the external quantum emission along the cavity axis and the spectral purity of emission from the films that are used as active media to realize a Si based RCLED (resonant cavity light emitting diode). These structures are realized by chemical vapour deposition on a silicon substrate. The microcavities are tuned at different wavelengths: 540nm, 980nm and 1540nm (characteristic emission wavelengths respectively for Tb, Yb and Er). The reflectivity of the microcavities is of 97% and the quality factor ranges from 60 (for the cavity tuned at 980nm) to 95 (for the cavities tuned at 540nm and 1540nm).

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