- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Synthesis, Photophysical and Electroluminescent Properties of Iridium(III) Complexes with 2-Aryl-thiazole and Oxadiazol-substituted Amide Derivative Ligands
摘要： By using aryl-thiazole as cyclometalated ligand and oxadiazol-substituted amide as ancillary ligand, three novel iridium(III) complexes have been synthesized and characterized, and the photophysical and electrochemical properties have been investigated. Complexes 1–3 exhibit efficient phosphorescence emissions at 542, 555 and 585 nm with photoluminescence quantum yields (PLQYs) of 0.04, 0.03 and 0.02 in CH3CN solutions, respectively. In the 10 wt% doped 2,4-diphenyl-6-bis(12-phenylindolo)[2,3-a]carbazole-11-yl)-1,3,5-triazine (Dictrz) film, the PLQYs (0.88 for complex 1, 0.47 for complex 2 and 0.37 for complex 3) increase significantly owing to the great restriction of rotations and vibrations in rigid host. The organic light-emitting diodes based on these complexes show good performance with the maximum current efficiencies of 20.06, 22.20 and 13.45 cd A-1 and maximum power efficiencies of 13.54, 17.31 and 9.48 lm W?1 with the CIE coordinates of (0.46, 0.53), (0.49, 0.50) and (0.59, 0.40) for complexes 1?3, respectively.
关键词： Iridium complex,Aryl-thiazole,Organic light-emitting diodes,Oxadiazol-substituted amide
更新于2025-11-19 16:56:35
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Novel hole blocking materials based on 2,6-disubstituted dibenzo[ <i>b</i> , <i>d</i> ]furan and dibenzo[ <i>b</i> , <i>d</i> ]thiophene segments for high-performance blue phosphorescent organic light-emitting diodes
摘要： Novel hole blocking materials (HBMs) based on 2,6-disubstituted dibenzo[b,d]furan and dibenzo[b,d]thiophene segments, 3,30,300,30 0 0-(dibenzo[b,d]furan-2,6-diylbis(benzene-5,3,1-triyl))tetrapyridine (26DBFPTPy) and 3,30,300,30 0 0-(dibenzo[b,d]thiophene-2,6-diylbis(benzene-5,3,1-triyl))tetrapyridine (26DBTPTPy), are successfully designed and synthesized for high-performance blue phosphorescent organic light-emitting diodes (PhOLEDs) for the first time. Computational simulation is used to investigate the optimal structure, orbital distribution, and physicochemical properties of both molecules. Thermal, optical, and electrochemical analysis shows that 26DBFPTPy and 26DBTPTPy possess high thermal stability, deep HOMO energy levels ((cid:2)7.08 and (cid:2)6.91 eV), and a high triplet energy (ET) (2.75 and 2.70 eV). Blue PhOLEDs with 26DBFPTPy or 26DBTPTPy as a hole blocking layer (HBL) exhibit a low turn-on voltage (3.0 V) and operating voltage (4.5 V) at 1000 cd m(cid:2)2. In addition, the blue PhOLEDs with 26DBFPTPy or 26DBTPTPy show superior external quantum e?ciencies (24.1 and 23.6%) and power e?ciencies (43.9 and 42.7 lm W(cid:2)1). They also show a very small e?ciency roll-o? of about 8.5% from 100 to 1000 cd m(cid:2)2. Furthermore, they exhibit improved lifetimes compared to the similarly designed HBL with a pyridine electron transport unit and a phenyl core structure.
关键词： dibenzo[b,d]furan,hole blocking materials,dibenzo[b,d]thiophene,blue phosphorescent organic light-emitting diodes,high-performance
更新于2025-11-14 15:32:45
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New blue phosphorescence from trifluorosulfonyl-substituted iridium complexes
摘要： For color-pure phosphorescence organic light emitting diodes (PHOLEDs), we synthesized the trifluoromethyl sulfonyl substituted ligand and two new blue Iridium complexes with perfluoro-sulfonyl group (SOCF3pic and SOCF3mpic). The both iridium complexes showed similar photophysical and thermal properties while the HOMO energy leves of two Iridium complexes slightly differnet to be -5.84 eV for SOCF3pic and -5.74 eV for SOCF3mpic, respectively. The device with the SOCF3mpic dopant exhibited higher device efficiencies of 7.17 cd/A and 3.7 % compared to that with the SOCF3pic dopant (4.03 cd/A and 2.78 %). Two-dimensional GIXD images of scattered X-ray intensity from surface to full depth for SOCF3pic-doped and SOCF3mpic-doped TCTA:4PTPS films were characterized for preferential orientation along the out-of-plane direction.
关键词： preferential orientation along the out-of-plane direction,blue phosphorescence,iridium complex,grazing incidence wide-angle X-ray diffraction,organic light emitting diodes
更新于2025-09-23 15:23:52
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Simultaneous Singlet–Singlet and Triplet–Singlet F?rster Resonance Energy Transfer from a Single Donor Material
摘要： For almost 70 years, F?rster resonance energy transfer (FRET) has been investigated, implemented into nowadays experimental nanoscience techniques, and considered in a manifold of optics, photonics and optoelectronics applications. Here, we demonstrate for the first time simultaneous and efficient energy transfer from both donating singlet and triplet states of a single photoluminescent molecular species. Using a biluminescent donor that can emit with high yield from both excited states at room temperature allows to apply the FRET framework to such a bimodal system. It serves as an exclusive model system where the spatial origin of energy transfer is exactly the same for both donating spin states involved. Of paramount significance are the facts that both transfers can easily be observed by eye and that F?rster theory is successfully applied to state lifetimes spanning over eight orders of magnitude.
关键词： organic light-emitting diodes,energy transfer,biluminescence,dual state FRET
更新于2025-09-23 15:23:52
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Monodisperse Six-Armed Starbursts based on Truxene-Cored Multibranched Oligofluorenes: Design, Synthesis, and Stabilized Lasing Characteristics
摘要： A series of monodisperse six-armed conjugated starbursts (Tr1F, Tr2F and Tr3F) containing a truxene core and multibranched oligofluorene bridges capped with diphenylamine (DPA) units has been designed, synthesized, and investigated as robust gain media for organic semiconductor lasers (OSLs). The influence of electron-rich DPA end-groups on their optoelectronic characteristics has been discussed at length. DPA cappers effectively raise HOMO levels of the starbursts, thus enhancing the hole injection and transport ability. Solution-processed electroluminescence devices based on the resulting six-armed starbursts exhibited efficient deep-blue electroluminescence with clear reduced turn-on voltages (3.2~3.5 V). Moreover, the resulting six-armed molecules showed stabilized electroluminescence and amplified spontaneous emission with low thresholds (27.4~63.9 nJ pulse-1), high net gain coefficients (80.1~101.3 cm-1), and small optical loss (2.6~4.4 cm-1). Distributed feedback OSLs made from Tr3F exhibited low lasing threshold of 0.31 kW/cm2 (at 465 nm). The results suggest that the construction of truxene-centered six-armed conjugated starbursts with the incorporation of DPA units can effectively enhance EL properties by precisely regulating the HOMO energy levels, and further optimizing their optical gain properties.
关键词： Organic gain media,Organic light-emitting diodes (OLEDs),Conjugated starburst molecules,Organic semiconductor lasers (OSLs),HOMO levels
更新于2025-09-23 15:22:29
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The Design of Fused Amine/Carbonyl System for Efficient Thermally Activated Delayed Fluorescence: Novel Multiple Resonance Core and Electron Acceptor
摘要： Multiple resonances induced thermally activated delayed fluorescence (MR-TADF) has great advantages in high color purity display. Up to now, current MR-TADF emitters are only based on the boron-nitrogen-containing fragment. Reported herein is a novel class of MR-TADF emitter, quinolino[3,2,1-de]acridine-5,9-dione (QAO), realized by the opposite resonance effect of the carbonyl and the nitrogen atoms, which is also the smallest TADF emitter reported so far. The QAO-based pure blue organic light-emitting diode achieves a maximum external quantum efficiency (EQEmax) of 19.4% with a small full width at half maximum of 39 nm. Moreover, tert-butyl modified QAO can be employed as an efficient electron acceptor to construct an efficient yellow-green evaporation and solution process feasible TADF emitter, 7-(tert-butyl)-3,11-bis(9,9-dimethylacridin-10(9H)-yl)quinolino[3,2,1-de]acridine-5,9-dione (QAO-DAd), with significantly improved performance as compared to the previous flexible diketone-based emitters.
关键词： organic light-emitting diodes,thermally activated delayed fluorescence,TADF emitter,multiple resonance effect,aromatic diketone
更新于2025-09-23 15:22:29
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Wearable, Luminescent Oxygen Sensor for Transcutaneous Oxygen Monitoring
摘要： We present a new concept for a wearable oxygen (O2) sensor for transcutaneous O2 pressure (tcpO2) monitoring by combining the technologies of luminescent gas sensing and wearable devices. O2 monitoring has been exhaustively studied given its central role in diagnosing various diseases. The ability to quantify the physiological distribution and real-time dynamics of O2 from subcellular to the macroscopic level is required to fully understand mechanisms associated with both normal physiological and pathological conditions. Despite its profound biological and clinical importance, few effective methods exist for noninvasively quantifying O2 in a physiological setting. The wearable sensor developed here consists of three components: a luminescent sensing film attached onto skin by a carbon tape, an organic light-emitting diode (OLED) as a light source, and an organic photodiode (OPD) as a light detector. All the components are solution-processable and integrated on a plane in a bandage-like configuration. To verify the performance, tcpO2 variations by pressure-induced occlusion were measured in the lower arm and a thumb by the wearable sensor, and the results were comparable to those measured by a commercial instrument. In addition to its flexibility, other features of this sensor render it a potential low-cost solution for the simultaneous monitoring of tcpO2 in any part of a body.
关键词： organic light-emitting diodes,transcutaneous oxygen monitoring,wearable sensors,luminescent oxygen sensing,organic photodiodes
更新于2025-09-23 15:21:21
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Simple molecular-engineering approach for enhancing orientation and out-coupling efficiency of thermally activated delayed fluorescent emitters without red-shifting emission
摘要： The inclusion of a tetraphenylbenzene (4Ph) unit in thermally activated delayed fluorescence (TADF) emitters is demonstrated as a novel strategy for greatly enhancing the horizontally oriented alignment of the emitters without shifting the emission spectrum to longer wavelengths. Doping of blue-emitting 4PhOXDDMAC or greenish-blue-emitting 4PhOXDPXZ into o-DiCbzBz host layers yielded much higher degrees of horizontally oriented alignment for the emitter (up to 92%) compared to when the 4Ph unit was excluded (69% and 75%, respectively). The enhanced alignment results in high out-coupling efficiencies of 24% and 35% in organic light-emitting diodes based on 4PhOXDDMAC and 4PhOXDPXZ, respectively, and boosts the external quantum efficiencies to values (8.8% and 29.2%, respectively) that are higher than would be expected for randomly oriented emitters (out-coupling efficiency of 20%). These enhancements are achieved while avoiding the red-shift that often occurs using the common strategy of increasing molecular length, and, thereby, conjugation, to increase orientation.
关键词： transition dipole moment,thermally activated delayed fluorescence,light out-coupling factor,molecular orientation,organic light-emitting diodes
更新于2025-09-23 15:21:21
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Green and Stable Processing of Organic Light-Emitting Diodes from Aqueous Nanodispersion
摘要： An imminent show-stopper for up-scaled production of printed thin-film electronics are the flammable and environmentally hazardous solvents used to dissolve the organic semiconductors. Especially in the case of wide-web large-area coating the development of toxic and flammable vapour during coating and drying poses serious health and safety risks. Processing the active materials from aqueous nanodispersion therefore offers a highly attractive alternative. In contrast to thin-film organic photovoltaics (OPV), nanoparticle-based organic light-emitting diodes (OLEDs) have so far received only little attention. The very high electrical field (~0.1 GV/m) poses rather “unforgiving” requirements regarding the topology, integrity and chemistry of the active layer, seemingly difficult to achieve using aqueous nanodispersions. In this work we show that it can be done. We present polymer light-emitting diodes (PLEDs) with active layers processed from nanodispersion. Through thorough optimization of the particle preparation and casting procedures, we obtain smooth, dense and intergral light-emitting nanoparticle films compatible with stable PLED operation. The performance of the nanoparticle PLEDs is on par with that of solution-cast reference devices. The devices exhibit low leakage current and turn-on voltage, no sign of degradation through voltage cycling, no current hysteresis and similar efficiencies.
关键词： organic light-emitting diodes,aqueous nanodispersion,green processing,nanoparticle films,polymer light-emitting diodes
更新于2025-09-23 15:21:01
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Enhanced optical efficiency and color purity for organic light-emitting diodes by finely optimizing parameters of nanoscale low-refractive index grid
摘要： To extract the confined waveguided light in organic light-emitting diodes (OLEDs), inserting a low refractive index (RI) periodic structure between the anode and organic layer has been widely investigated as a promising technology. However, the periodic-structure-based light extraction applied inside devices has been shown to severely distort spectrum and affect EL characteristics. In this study, a simple light extraction technology using periodic low-RI nanodot array (NDA) as internal light extraction layer has been demonstrated. The NDA was fabricated simply via laser interference lithography (LIL). The structural parameters of periodic pattern, distance, and height were easily controlled by the LIL process. From computational analysis using finite-difference time-domain (FDTD) method, the NDA with 300 nm pitch and 0.3 coverage ratio per unit cell with 60 nm height showed the highest enhancement with spectral-distortion-minimized characteristics. Through both computational and experimental systematic analysis on the structural parameters of low-RI NDA-embedded OLEDs, highly efficient OLEDs have been fabricated. Finally, as representative indicators, hexagonal and rectangular positioned NDA-embedded OLEDs showed highly improved external quantum efficiencies of 2.44 (+29.55%) and 2.77 (+57.38%), respectively. Furthermore, the disadvantage originating from the nanoscale surface roughness on the transparent conductive oxide was minimized.
关键词： organic light-emitting diodes,nanodot array,FDTD simulation,laser interference lithography,light extraction,low refractive index
更新于2025-09-23 15:21:01