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.

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 Solution-Processed Efficient Blue Phosphorescent Organic Light-Emitting Diodes (PHOLEDs) Enabled by Hole-Transport Material Incorporated Single Emission Layer

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 554
Author(s):  
Taeshik Earmme
Keyword(s):  
Light Emitting Diodes ◽  
Blue Emission ◽  
Hole Transport ◽  
Organic Light Emitting Diodes ◽  
Emission Layer ◽  
Solution Processed ◽  
Light Emitting ◽  
Organic Light ◽  
Single Emission ◽  
Blue Phosphorescent

Solution-processed blue phosphorescent organic light-emitting diodes (PHOLEDs) based on a single emission layer with small-molecule hole-transport materials (HTMs) are demonstrated. Various HTMs have been readily incorporated by solution-processing to enhance hole-transport properties of the polymer-based emission layer. Poly(N-vinylcarbazole) (PVK)-based blue emission layer with iridium(III) bis(4,6-(di-fluorophenyl)pyridinato-N,C2′)picolinate (FIrpic) triplet emitter blended with solution-processed 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) gave luminous efficiency of 21.1 cd/A at a brightness of 6220 cd/m2 with an external quantum efficiency (EQE) of 10.6%. Blue PHOLEDs with solution-incorporated HTMs turned out to be 50% more efficient compared to the reference device without HTMs. The high hole mobility, high triplet energy of HTM, and favorable energy transfer between HTM blended PVK host and FIrpic blue dopant were found to be important factors for achieving high device performance. The results are instructive to design and/or select proper hole-transport materials in solution-processed single emission layer.

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.

Optimization for white organic light-emitting diode based on DCJTB as color conversion layer

2018 ◽  
Vol 32 (27) ◽  
pp. 1850299
Author(s):  
Pei Wang ◽  
Zhen Wang ◽  
Ai Chen ◽  
Jia-Feng Xie ◽  
Xin Zheng
Keyword(s):  
Current Efficiency ◽  
Current Density ◽  
White Light ◽  
Power Efficiency ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
High Efficient ◽  
Color Conversion

In this paper, combining phosphorescence and fluorescence to form white light was realized based on DCJTB:PMMA/ITO/NPB/TCTA/FIrpic:TCTA/TPBi/Ir(ppy)3:TPBi/TPBi/Cs2CO3/Al. The effects of red fluorescence on this white light device was studied by adjusting the concentration of DCJTB. The study shows that the device with a DCJTB concentration of 0.7% in the color conversion layer (CCL) generates a peak current efficiency and power efficiency of 23.4 cd ⋅ A[Formula: see text] and 7.5 lm ⋅ W[Formula: see text], respectively. And it is closest to the equal-energy white point of (0.33, 0.33) which shows a CIE (Commission Internationale de L’Eclairage) coordinate of (0.35, 0.43) and a color rendering index (CRI) of 70 at current density of 10 mA ⋅ cm[Formula: see text]. In order to improve the efficiency, we design and fabricate both high efficient and pure white organic light-emitting diode (WOLED) by replacing the single blue emission layer (EML) with double EMLs of FIrpic:TCTA and FIrpic:TPBi. The further study shows that, when the layers of EML is three and the concentration of DCJTB at 0.7%, the device exhibits good performance specifically, at current density of 10 mA ⋅ cm[Formula: see text], the current efficiency of 28.2 cd ⋅ A[Formula: see text] (power efficiency of 10.3 lm ⋅ W[Formula: see text]), and the CIE coordinate of (0.33, 0.31) (CRI of 80.38).

scholarly journals A hybrid inorganic–organic light-emitting diode using Ti-doped ZrO2 as an electron-injection layer

RSC Advances ◽  
2018 ◽  
Vol 8 (15) ◽  
pp. 8402-8411 ◽  
Author(s):  
Jayaraman Jayabharathi ◽  
Sekar Panimozhi ◽  
Venugopal Thanikachalam ◽  
Annadurai Prabhakaran ◽  
Palanivel Jeeva
Keyword(s):  
Current Efficiency ◽  
Power Efficiency ◽  
Light Emitting Diode ◽  
Electron Injection ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Electron Injection Layer ◽  
Organic Light

Ti-doped ZrO2 facilitates electron injection effectively, leading to enhanced current efficiency of 2.84 cd A−1 and power efficiency of 1.32 lm W−1

High performance solution-processed green phosphorescent organic light-emitting diodes with high current efficiency and long-term stability

2019 ◽  
Vol 7 (37) ◽  
pp. 11569-11580 ◽  
Author(s):  
Athithan Maheshwaran ◽  
Vijaya Gopalan Sree ◽  
Ho-Yeol Park ◽  
Woosum Cho ◽  
Hyein Kim ◽  
...  
Keyword(s):  
Current Efficiency ◽  
High Performance ◽  
Organic Light Emitting Diodes ◽  
High Current ◽  
Solution Processed ◽  
High Current Efficiency ◽  
Light Emitting ◽  
Long Term Stability ◽  
Organic Light

Highly efficient (D–π–A)-type host and green Ir(iii) complexes are introduced for solution-processed PHOLEDs that achieve high CE with considerably high EQE. The devices with symmetrical complex show more stable than those with asymmetrical complex.

Power-efficient solution-processed red organic light-emitting diodes based on an exciplex host and a novel phosphorescent iridium complex

2016 ◽  
Vol 4 (24) ◽  
pp. 5787-5794 ◽  
Author(s):  
Xuejing Liu ◽  
Bing Yao ◽  
Zilong Zhang ◽  
Xiaofei Zhao ◽  
Baohua Zhang ◽  
...  
Keyword(s):  
Power Efficiency ◽  
Efficient Solution ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Iridium Complex ◽  
Solution Processed ◽  
Power Efficient ◽  
Light Emitting ◽  
Organic Light ◽  
Cie Coordinates

A novel red heteroleptic iridium complex, Ir(DPA-Flpy-CF3)2acac, was synthesized and whose corresponding solution-processed PhOLED shows a record power efficiency of 44.5 lm W−1 with CIE coordinates of (0.64, 0.36).

Towards high-power-efficiency solution-processed OLEDs: Material and device perspectives

2020 ◽  
Vol 140 ◽  
pp. 100547 ◽  
Author(s):  
Shumeng Wang ◽  
Hongyang Zhang ◽  
Baohua Zhang ◽  
Zhiyuan Xie ◽  
Wai-Yeung Wong
Keyword(s):  
High Power ◽  
Power Efficiency ◽  
Solution Processed ◽  
High Power Efficiency
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