Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Solution-processed transparent blue organic light-emitting diodes with graphene as the top cathode.

ABSTRACT: Graphene thin films have great potential to function as transparent electrodes in organic electronic devices, due to their excellent conductivity and high transparency. Recently, organic light-emitting diodes (OLEDs)have been successfully demonstrated to possess high luminous efficiencies with p-doped graphene anodes. However, reliable methods to fabricate n-doped graphene cathodes have been lacking, which would limit the application of graphene in flexible electronics. In this paper, we demonstrate fully solution-processed OLEDs with n-type doped multilayer graphene as the top electrode. The work function and sheet resistance of graphene are modified by an aqueous process which can also transfer graphene on organic devices as the top electrodes. With n-doped graphene layers used as the top cathode, all-solution processed transparent OLEDs can be fabricated without any vacuum process.

SUBMITTER: Chang JH

PROVIDER: S-EPMC4402614 | biostudies-other | 2015

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Yb:MoO3/Ag/MoO3 Multilayer Transparent Top Cathode for Top-Emitting Green Quantum Dot Light-Emitting Diodes.

Project description:In this study, we report on the application of a dielectric/ultra-thin metal/dielectric (DMD) multilayer consisting of ytterbium (Yb)-doped molybdenum oxide (MoO3)/silver (Ag)/MoO3 stacked as the transparent cathode in top-emitting green quantum dot light-emitting diodes (QLED). By optimizing the Yb doping ratio, we have highly improved the electron injection ability from 0.01 to 0.35. In addition, the dielectric/ultra-thin metal/dielectric (DMD) cathode also shows a low sheet resistance of only 12.2 ?/sq, which is superior to the resistance of the commercially-available indium tin oxide (ITO) electrode (~15 ?/sq). The DMD multilayer exhibits a maximum transmittance of 75% and an average transmittance of 70% over the visible range of 400-700 nm. The optimized DMD-based G-QLED has a smaller current leakage at low driving voltage. The optimized DMD-based G-QLED enhances the current density than that of G-QLED with indium zinc oxide (IZO) as a cathode. The fabricated DMD-based G-QLED shows a low turn-on voltage of 2.2 V, a high current efficiency of 38 cd/A, and external quantum efficiency of 9.8. These findings support the fabricated DMD multilayer as a promising cathode for transparent top-emitting diodes.

| S-EPMC7221779 | biostudies-literature

Flexion bonding transfer of multilayered graphene as a top electrode in transparent organic light-emitting diodes.

Project description:Graphene has attracted considerable attention as a next-generation transparent conducting electrode, because of its high electrical conductivity and optical transparency. Various optoelectronic devices comprising graphene as a bottom electrode, such as organic light-emitting diodes (OLEDs), organic photovoltaics, quantum-dot LEDs, and light-emitting electrochemical cells, have recently been reported. However, performance of optoelectronic devices using graphene as top electrodes is limited, because the lamination process through which graphene is positioned as the top layer of these conventional OLEDs is a lack of control in the surface roughness, the gapless contact, and the flexion bonding between graphene and organic layer of the device. Here, a multilayered graphene (MLG) as a top electrode is successfully implanted, via dry bonding, onto the top organic layer of transparent OLED (TOLED) with flexion patterns. The performance of the TOLED with MLG electrode is comparable to that of a conventional TOLED with a semi-transparent thin-Ag top electrode, because the MLG electrode makes a contact with the TOLED with no residue. In addition, we successfully fabricate a large-size transparent segment panel using the developed MLG electrode. Therefore, we believe that the flexion bonding technology presented in this work is applicable to various optoelectronic devices.

| S-EPMC4667220 | biostudies-literature

High-Energy-Level Blue Phosphor for Solution-Processed White Organic Light-Emitting Diodes with Efficiency Comparable to Fluorescent Tubes.

Project description:A high-energy-level blue phosphor FIr-p-OC8 has been developed for solution-processed white organic light-emitting diodes (WOLEDs) with comparable fluorescent tube efficiency. Benefiting from the electron-donating nature of the introduced alkoxy, FIr-p-OC8 shows not only efficient blue light but also elevated highest occupied molecular orbital/lowest unoccupied molecular orbital levels to well match the dendritic host H2. Consequently, the hole scattering between FIr-p-OC8 and H2 can be prevented to favor the direct exciton formation on the blue phosphor, leading to reduced driving voltage and thus improved power efficiency. By exploiting this approach, a maximum power efficiency of 68.5 lm W-1 is achieved for FIr-p-OC8-based white devices, slightly declining to 47.0 lm W-1 at a practical luminance of 1,000 cd m-2. This efficiency can be further raised to 96.3 lm W-1 @ 1,000 cd m-2 when a half-sphere is applied to increase light out-coupling. We believe that our results can compete with commercial fluorescent tubes, representing an important progress in solution-processed WOLEDs.

| S-EPMC6137322 | biostudies-literature

Solution processed organic light-emitting diodes using a triazatruxene crosslinkable hole transporting material.

Project description:A cross-linkable triazatruxene that leads to insoluble films upon thermal annealing at temperatures compatible with flexible substrates is presented. The films were used as the hole transporting and electron blocking layer in partially solution processed phosphorescent organic light-emitting diodes, reaching power conversion efficiencies of 24 lm W-1, an almost 50% improvement compared to the same OLEDs without the cross-linkable hole transporting layer.

| S-EPMC9087953 | biostudies-literature

Design of efficient thermally activated delayed fluorescence blue host for high performance solution-processed hybrid white organic light emitting diodes.

Project description:Developing a solution-processible blue thermally activated delayed fluorescence (TADF) emitter for hybrid white organic light emitting diodes (WOLEDs) is still a challenge. In this work, two TADF blue emitters are designed and synthesized to explore a common strategy to qualify the small molecular TADF material as a solution-processible blue host. Systematic studies find that the molecular encapsulation by introducing unconjugated carbazoles as steric shields not only keeps the intrinsic TADF feature unchanged, but also effectively suppress the intermolecular interaction induced exciton quenching, which makes the material more efficient for solution-processing. The optimized solution-processed hybrid WOLEDs based on the encapsulated TADF blue host realized a highly efficient device performance with a maximum current efficiency (CE), power efficiency (PE) and external quantum efficiency (EQE) of 45.6 cd A-1, 40.9 lm W-1 and 17.0%, respectively, which are three times higher in device efficiency and twenty times higher in device lifetime than the corresponding device with an unencapsulated TADF blue host. Furthermore, the obtained device exhibits a high electroluminescence (EL) above 20 000 cd m-2 and a stable EL spectrum with nearly unchanged Commission International de L'Eclairage (CIE) coordinate at a wide range of applied voltages. These results clearly demonstrate that the molecular encapsulation of the TADF blue host is a superior and promising strategy to achieve high performance and color stable solution-processed hybrid WOLEDs.

| S-EPMC6428138 | biostudies-literature

A solution processed flexible nanocomposite electrode with efficient light extraction for organic light emitting diodes.

Project description:Highly efficient organic light emitting diodes (OLEDs) based on multiple layers of vapor evaporated small molecules, indium tin oxide transparent electrode, and glass substrate have been extensively investigated and are being commercialized. The light extraction from the exciton radiative decay is limited to less than 30% due to plasmonic quenching on the metallic cathode and the waveguide in the multi-layer sandwich structure. Here we report a flexible nanocomposite electrode comprising single-walled carbon nanotubes and silver nanowires stacked and embedded in the surface of a polymer substrate. Nanoparticles of barium strontium titanate are dispersed within the substrate to enhance light extraction efficiency. Green polymer OLED (PLEDs) fabricated on the nanocomposite electrode exhibit a maximum current efficiency of 118?cd/A at 10,000?cd/m(2) with the calculated external quantum efficiency being 38.9%. The efficiencies of white PLEDs are 46.7?cd/A and 30.5%, respectively. The devices can be bent to 3?mm radius repeatedly without significant loss of electroluminescent performance. The nanocomposite electrode could pave the way to high-efficiency flexible OLEDs with simplified device structure and low fabrication cost.

| S-EPMC3955904 | biostudies-literature

Ultrahigh-efficiency solution-processed simplified small-molecule organic light-emitting diodes using universal host materials.

Project description:Although solution processing of small-molecule organic light-emitting diodes (OLEDs) has been considered as a promising alternative to standard vacuum deposition requiring high material and processing cost, the devices have suffered from low luminous efficiency and difficulty of multilayer solution processing. Therefore, high efficiency should be achieved in simple-structured small-molecule OLEDs fabricated using a solution process. We report very efficient solution-processed simple-structured small-molecule OLEDs that use novel universal electron-transporting host materials based on tetraphenylsilane with pyridine moieties. These materials have wide band gaps, high triplet energy levels, and good solution processabilities; they provide balanced charge transport in a mixed-host emitting layer. Orange-red (~97.5 cd/A, ~35.5% photons per electron), green (~101.5 cd/A, ~29.0% photons per electron), and white (~74.2 cd/A, ~28.5% photons per electron) phosphorescent OLEDs exhibited the highest recorded electroluminescent efficiencies of solution-processed OLEDs reported to date. We also demonstrate a solution-processed flexible solid-state lighting device as a potential application of our devices.

| S-EPMC5091357 | biostudies-literature

Solution-Processed Yellow Organic Light-Emitting Diodes Based on Two New Ionic Ir (III) Complexes.

Project description:Two new and efficient cationic yellow-emissive Ir (III) complexes (Ir1 and Ir2) are rationally designed by using 2-(4-chloro-3-(trifluoromethyl)phenyl)-4-methylquinoline as the main ligand, and, respectively, 4,4'-dimethyl-2,2'-bipyridyl and 4,4'-dimethoxy-2,2'-bipyridyl as the ancillary ligands. Both complexes show enhanced phosphorescence (546 nm with 572 nm as shoulder and high phosphorescent quantum efficiency in solution, which is in favor of efficient solution-processed phosphorescent organic light-emitting diodes. Compared with Ir2, the Ir1-based device displays excellent device performance, with maximum external quantum efficiency, current efficiency, and power efficiency of up to 7.92%, 26.32 cd/A and 15.31 lm/W, respectively, thus proving that the two new ionic Ir (III) complexes exhibit great potential for future solution-processed electroluminescence.

| S-EPMC9101346 | biostudies-literature

Indolocarbazole-Based Photo-Crosslinkable Hole-Transporting Layer for Efficient Solution-Processed Organic Light-Emitting Diodes.

Project description:We designed and synthesized a new indolocarbazole-based polymer, poly(N,N-diphenyl(5,11-dihexylindolo[3,2,1-jk]carbazol-2-yl)amine) (PICA), for solution-processed organic light-emitting diodes (OLEDs). The highest occupied and lowest unoccupied molecular orbital energy levels of this polymer, -5.25 and -2.46 eV, respectively, are suitable for hole transport from the anode to the emissive layer. PICA was photo-crosslinked by UV irradiation with ethane-1,2-diyl bis(4-azido-2,3,5,6-tetrafluorobenzoate) (FPA) as the photoinitiator. Successful crosslinking was confirmed by a decreased intensity in the azide-stretching FT-IR peak and solvent test with toluene (a suitable solvent for PICA). The PICA film photo-crosslinked with 3 wt% FPA showed enhanced solvent resistance (90%) compared to the non-crosslinked neat PICA film (<20%). Moreover, OLED devices using PICA-based hole-transporting layers exhibited better device performance (EQE/LE/PE: 8.88%/12.97/8.12 in red devices, 10.84%/38.47 cd/A/25.06 lm/W in green devices) than those using poly-TPD:FPA. We demonstrated that the photo-crosslinked PICA can be applied as a hole-transporting layer in solution-processed OLEDs.

| S-EPMC10343803 | biostudies-literature

Highly efficient organic light emitting diodes formed by solution processed red emitters with evaporated blue common layer structure.

Project description:We prepared highly-efficient solution-processed red phosphorescent organic light emitting diodes (PHOLEDs) with a blue common layer structure that can reasonably confine the triplet excitons inside of the red emission layer (EML) with the assistance of a bipolar exciton blocking layer. The red PHOLEDs containing EML with a 7 : 3 ratio of 11-(4,6-diphenyl-[1,3,5]triazin-2-yl)-12-phenyl-11,12-dihydro-11,12-diaza-indeno[2,1-a]fluorene (n-type host, NH) : 4-(3-(triphenylen-2-yl)phenyl)dibenzo[b,d]thiophene (p-type host, PH) doped with 5% Iridium(III) bis(2-(3,5-dimethylphenyl)quinolinato-N,C2')tetramethylheptadionate (Red Dopant, RD) produced the highest current and power efficiencies at 23.4 cd/A and 13.6 lm/W, with a 19% external quantum efficiency at 1000 cd/m(2). To the best of our knowledge, such efficiency was the best among those that have been obtained from solution-processed small molecular red PHOLEDs. In addition, the host molecules utilized in this study have no flexible spacers, such as an alkyl chain, which normally deteriorate the stability of the device.

| S-EPMC4626861 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data