- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A new strategy for structuring white organic light-emitting diodes by combining complementary emissions in the same interface
摘要： In this work, we proposed a new strategy for structuring white organic light-emitting diodes (WOLEDs) using all exciplex emissions, where the white devices can be fabricated by simply depositing several exciplex acceptor layers on the same exciplex donor layer in a vertical direction, and complementary exciplex emissions can be realized in the same exciplex donor layer interface for forming white emission. Based on this new strategy, a series of WOLEDs with different array arrangements of different exciplex acceptor layers on the same exciplex donor layer were demonstrated. The device with a bisected blue-yellow exciplex acceptor layer on the same exciplex donor layer realizes good two-color white emission with a high color rendering index of 71, and also achieves a high current efficiency of 3.17 cd A?1. Moreover, the emission spectra and device performance of white devices can be adjusted and improved by simply changing the array arrangements of different exciplex acceptor layers on the same exciplex donor layer. More importantly, the proposed new strategy can effectively solve the interface problem induced by employing interface exciplexes to realize multi-color white emission, which provides a new approach to accomplish all exciplex emission WOLEDs.
关键词： exciplex emissions,device performance,color rendering index,white organic light-emitting diodes,current efficiency
更新于2025-09-16 10:30:52
-
Mixed-Host Systems with a Simple Device Structure for Efficient Solution-Processed Organic Light-Emitting Diodes of a Red-Orange TADF Emitter
摘要： Charge balance, concentration quenching, and exciton con?nement are the most important factors for realizing the use of thermally activated delayed ?uorescence (TADF) emitters for organic light-emitting diodes. Red-orange organic light-emitting diodes of a TADF emitter 2-[4 (diphenylamino)phenyl]-10,10-dioxide-9H-thioxanthen-9-one (TXO-TPA) have been reported by doping in a mixed p-type host system of poly(N-vinylcarbazole) (PVK) and 1,3-bis(N-carbazolyl)benzene (mCP) via solution-processed. We have demonstrated the peak external quantum e?ciency of 9.75%, maximum current e?ciency of 19.36 cd/A, and power e?ciency of 12.17 lm/W along with a CIE coordinate of (0.45, 0.51). The devices were compared with di?erent doping concentrations of TXO-TPA, and a comparative investigation on the e?ect of the thickness electron transport layer was studied. The results clearly indicated that this solution-processed TXO-TPA device structure is a promising strategy to develop highly e?cient but simple OLED structures.
关键词： external quantum e?ciency,thermally activated delayed ?uorescence,red-orange,solution-processed,organic light-emitting diodes
更新于2025-09-16 10:30:52
-
New Class of Supramolecular Bowl-Shaped Columnar Mesogens Derived from Thiacalix[4]arene Exhibiting Gelation and Organic Light-Emitting Diodes Applications
摘要： A new class of blue light-emitting bowl-shaped mesogens with the thiacalix[4]arene core appended with 1,3,4-thiadiazole derivatives having peripheral alkoxy side chains have been synthesized and well characterized. The liquid crystalline behavior of present synthesized derivatives was examined by optical polarizing microscopy, di?erential scanning calorimetry, and X-ray di?raction studies. It was observed that these thiacalix[4]arene derivatives were capable of stabilizing the observed Colh phase with a higher temperature range. The cone-shaped thiacalix[4]-arene-based liquid crystals with peripheral alkoxy side chains able to pack into the interactions and thermal behavior. All derivatives showed blue luminescence in solution, solid thin-?lm, and gelation state. The hexagonal columnar phase and emissive nature of thiadiazole-based thiacalixarene compounds having xerogel behavior make them favorable in the application of emissive electronic display devices. The electrochemical properties of these thiacalixarene-based compounds demonstrate the e?ect of alkyl side chain on the highest occupied molecular orbital?lowest unoccupied molecular orbital energy levels and also exhibited lower electron band gaps. The electroluminescence behavior of the compound 10c was examined as emissive layers in the fabrication of organic light-emitting diodes.
关键词： thiacalix[4]arene,bowl-shaped mesogens,blue light-emitting,organic light-emitting diodes,1,3,4-thiadiazole derivatives,liquid crystalline behavior
更新于2025-09-12 10:27:22
-
[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Towards Solution-Processed Top-Emitting OLEDs Using a Phosphorescent Iridium Complex
摘要： Phosphorescent inverted top-emitting OLEDs using green iridium complexes have been fabricated by spin coating and their performances compared to bottom-emitting OLEDs based on the same materials. Even if the current efficiency is lower, respectively 7.0 ± 1.1 cd.A-1 and 12.9 ± 1.9 cd.A-1, this paper demonstrates the feasibility to fabricate phosphorescent top-emitting OLEDs by using a solution process with a simple OLED structure and replacing indium tin oxide electrode by a low-cost reflective aluminum electrode. Optical characterization of the top-emitting OLEDs shows a low emission shift compared to the spectrum of bottom-emitting OLED. A low angle dependency of the electroluminescence peak wavelength is observed , showing it is possible to control and minimize the microcavity effects for solution-processed top-emitting OLEDs.
关键词： phosphorescent emitters,solution process,top-emitting organic light-emitting diodes (OLEDs)
更新于2025-09-12 10:27:22
-
J-aggregation Enhances the Electroluminescence Performance of Sky-blue TADF Emitter in Non-doped OLEDs
摘要： A pivotal thermally activated delayed fluorescence (TADF) emitter DspiroAc-TRZ was developed, and it exhibits greatly enhanced electroluminescence performance in non-doped organic light-emitting diodes (OLEDs) owing to the concurrent manipulation of aggregation behavior and monomolecular structure. The delicate non-planar packing pattern in DspiroAc-TRZ crystal can not only lead to highly efficient solid-state luminescence, but also form loose intermolecular packing pattern, greatly decreasing the HOMOs or LUMOs overlaps in dimers and shortening triplet exciton diffusion length. In addition, the rigid donor and acceptor moieties in DspiroAc-TRZ can rigidify the molecular backbone, resulting in tiny geometry vibrational relaxation in excited state. Impressively, high photoluminescent quantum yields (PLQYs) of 78.5% and 83.7% were achieved for DspiroAc-TRZ single-crystal and non-doped film. A high external quantum efficiency (EQE) of 25.7% was achieved in non-doped sky-blue TADF-OLED, which is higher than any reported EQE values of non-doped sky-blue TADF-OLEDs so far.
关键词： molecular orientation,non-doped,thermally activated delayed fluorescence,organic electronics,organic light-emitting diodes
更新于2025-09-12 10:27:22
-
Tetraphenylimidazole-based luminophores for explosive chemosensors and OLEDs: experimental and theoretical investigation
摘要： Four different small molecular weight tetraphenylimidazole (TPI) derivatives were synthesized and characterized. The photophysical properties, solvatochromism, ?uorescence decays and electrochemical behaviours were discussed. All luminophores showed very high selectivity towards picric acid (PA) among all other nitroaromatics. All synthesized TPI luminophores showing good selectivity and high sensitivity, not only can detect PA in solution but can also be used in the contact mode for PA in thin-layer chromatography plates. The sensing mechanism was carefully studied by using nuclear magnetic resonance and density functional theory (DFT) studies. The optimal geometries and singlettriplet levels were calculated theoretically by using DFT and time-dependent DFT methods. Furthermore, examinations were carried out to know the optical, electronic, charge transport and stability properties of TPI derivatives as emissive and charge transport materials for organic light-emitting devices (OLEDs). Furthermore, all the TPI derivatives were used as emissive component for fabrication of OLED devices (I and II types) with multilayer con?guration via solution process. The device con?gurations are ITO/PEDOT:PSS/CBP:TPI-1, TPI-2, TPI-3 and TPA-4/TPBi/LiF/Al and ITO/PEDOT:PSS/TPI-1, TPI-2, TPI-3 and TPA-4/TPBi/LiF/Al for doped (device II) and non-doped (device I) devices, respectively. Compared with all, the luminophores containing non-?uorinated linker (CH3-phenyl) showed deep-blue electroluminescence (Commission International de L'Eclairage [CIE], x ? 0.20, y ? 0.17), whereas the ?uorinated linker (CF3-phenyl) containing luminophores exhibited bright-blue emission (CIE, x ? 0.23, y ? 0.21) with 1.4% external quantum ef?ciency.
关键词： Organic light emitting diodes,Sensing,DFT and TD-DFT,Lifetime
更新于2025-09-12 10:27:22
-
Violet/deep-blue fluorescent organic light-emitting diode based on high-efficiency novel carbazole derivative with large torsion angle
摘要： A novel and highly efficient violet/deep-blue fluorescent carbazole and naphthalene-based compound (1) is designed and synthesized. The compound shows intensive violet/deep-blue fluorescence, high photoluminescence efficiency (0.72 in CH2Cl2, 0.65 in film) and narrow full width at half maximum (48 nm). The large torsion angles between carbazole and naphthalene guarantee the weak intermolecular interactions and suppress the π-π interactions in solid state, resulting in the highly efficient violet/deep-blue fluorescence. The maximum emission peak, luminance and external quantum efficiency for violet/deep-blue electroluminescence are 410 nm, 1326 cd/m2 and ～2%, respectively.
关键词： Carbazole,Naphthalene,Violet/deep-blue fluorescence,Organic light-emitting diodes
更新于2025-09-12 10:27:22
-
Roles of Ancillary Chelates and Overall Charges of Bis-Tridentate Ir(III) Phosphors for OLED Applications
摘要： A series of charge-neutral bis-tridentate Ir(III) complexes (1, 3 and 4) were prepared via employing three distinctive tridentate pro-chelates, i.e., (pzptBphFO)H2, [(phpyim)H2·(PF6)] and [(pimb)H3·(PF6)2], which possess one dianionic pzptBphFO, together with a second monoanionic tridentate chelate, namely: (pzptBphFO)H, phpyim, and pimb, respectively. Moreover, homoleptic, charge-neutral complex 2 was obtained by methylation of chelating (pzptBphFO)H of 1 in basic media, while closely related cationic complexes 5 – 7 were obtained by further methylation of remaining pyrazolate unit of previously mentioned neutral complexes 2 – 4, followed by anion metatheses. All of these Ir(III) metal complexes showed broadened emission profile with an onset at ～450 nm, a result of enlarged ligand-centered ππ* transition gap, but with distinct efficiencies ranging from 0.8% to nearly unitary. Comprehensive spectroscopic as well as computational approaches were executed, providing a correlation for the emission efficiencies versus energy gaps, and between the metal-to-ligand charge transfer (MLCT)/ππ* emitting excited state and upper lying metal-centered dd quenching state. Furthermore, Ir(III) complexes 3 and 4 were selected as dopant emitters in fabrication of sky-blue phosphorescent OLEDs, affording max. external quantum efficiencies of 16.7% and 14.6% and with CIEx,y coordinates of (0.214, 0.454) and (0.191, 0.404) at current density of 102 cd/m2, respectively. Hence, this research highlights an inherent character of bis-tridentate Ir(III) complexes in achieving high phosphorescence quantum yield at molecular level.
关键词： Metal-centered dd excited state,Metal to ligand charge transfer,Phosphors,Organic light emitting diodes,Iridium
更新于2025-09-12 10:27:22
-
Molecular Engineering of Thermally Activated Delayed Fluorescence Emitters with Aggregation-Induced Emission via Introducing Intramolecular Hydrogen-Bonding Interactions for Efficient Solution-Processed Nondoped OLEDs
摘要： Purely organic luminescent materials concurrently exhibiting thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) features are in great demand due to their high efficiency in aggregation-state toward efficient non-doped OLEDs. Herein, a class of thermally activated delayed fluorescence (TADF) emitters adopting phenyl(pyridyl)methanone as electron-accepting segment and di(tert-butyl)carbazole and 9,9-dimethyl-9,10-dihydroacridine (or phenoxazine) as electron-donating groups are designed and synthesized. The existence of intramolecular hydrogen bonding is conducive to minish the energy difference between singlet and triplet (ΔEst), suppress non-radiative decay and increase the luminescence efficiency. By using 3CPyM-DMAC as emitter, the non-doped device via solution process realize high current efficiency (CE) and external quantum efficiency (EQE) of 35.4 cd A-1 and 11.4 %, respectively, which is superior to that of CBM-DMAC with CE and EQE of 14.3 cd A-1 and 6.7 %. This work demonstrates a promising tactics to the establishment of TADF emitters with AIE features via introducing intramolecular hydrogen-bonding.
关键词： organic light-emitting diodes (OLEDs),nondoped,thermally activated delayed fluorescence (TADF),solution processed,aggregation-induced emission (AIE)
更新于2025-09-12 10:27:22
-
Fluorination of pyrene-based organic semiconductors enhances the performance of light emitting diodes and halide perovskite solar cells
摘要： In this work, a fluorinated pyrene-based organic semiconductor (L-F) has been designed and synthesized starting from a low-cost pyrene core functionalized with triphenilamine substituents at 1,3,6,8 positions (L-H), obtained via Suzuki coupling reactions. Its performance when used as green emitter in organic light emitting diodes (OLEDs) or as dopant-free hole-transporting material (HTM) in halide perovskite solar cells (PSCs) is higher than the L-H counterpart, in spite of its lower bulk hole-mobility (7.0 x 10-6 cm2/Vs) with respect to L-H (1.9 x 10-4 cm2/Vs). In fact, the OLED devices based on L-F active layer showed excellent green emission (brightness and current efficiency were1759.8 cd/m2 and 3.7 cd/A, respectively) at a 4.5 V turn-on voltage. When the molecules were employed as a dopant-free HTM in PSCs, L-F led to a power conversion efficiency (PCE) and open circuit voltage (Voc) of 5.9 % and 1.07 V, respectively, thus outperforming those of corresponding devices based on L-H (PCE = 5.0% and Voc = 0.87 V) under similar experimental conditions (AM 1.5G and 100 mW cm2). We attribute the enhancements of L-F-based optoelectronic devices (OLEDs and PSCs) to the observed better quality of theL-F films. The promising performance of L-F indicates that fluorination of small molecules can be an effective strategy to achieve low-cost and high-performing materials for energy harvesting and display-based organic electronic devices.
关键词： pyrene,perovskite solar cells,hole transporting material,triphenylamine,fluorination,dopant-free,organic light emitting diodes
更新于2025-09-12 10:27:22