Browse
Submit Data
Databases
API
Help

Dataset Information

15 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Controlling excimer formation in indolo[3,2,1-jk]carbazole/9H-carbazole based host materials for RGB PhOLEDs.

ABSTRACT: Three novel materials (5CzICz, Cz₂ICz and Cz₃ICz), based on the indolo[3,2,1-jk]carbazole and 9H-carbazole building blocks, with high triplet energies (E _T > 2.80 eV) and good thermal stability (T _g > 101 °C) were synthesized, characterized and applied as host materials in PhOLED devices. In course of the preparation of the materials, an improved protocol for the synthesis of the indolo[3,2,1-jk]carbazole moiety has been developed. The careful molecular design of the title compounds allowed to avoid excimer formation of the indolo[3,2,1-jk]carbazole subunits in thin films. Therefore, the improved molecular design broadened the applicability of indolo[3,2,1-jk]carbazole host materials and significantly enhanced the efficiency of PhOLED devices based on these derivatives compared to previously reported indolo[3,2,1-jk]carbazole based compounds. Accordingly, employing the newly developed materials red (CE_max: 32.7 cd A^-1, PE_max: 31.0 lm W^-1, EQE_max: 20.4%), green (CE_max: 81.0 cd A^-1, PE_max: 87.4 lm W^-1, EQE_max: 21.5%) and blue (CE_max: 35.5 cd A^-1, PE_max: 39.9 lm W^-1, EQE_max: 18.0%) PhOLED devices with a remarkably low efficiency roll-off at 1000 cd m^-2 (Cz₂ICz - red: 5%; green: 0%; blue: 6%) were fabricated.

SUBMITTER: Zhao C

PROVIDER: S-EPMC6167949 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Multi-Resonant Indolo[3,2,1-<i>jk</i>]carbazole-Based Host for Blue Phosphorescent Organic Light-Emitting Diodes.

Project description:In organic light-emitting diodes, positive and negative charge carriers mostly migrate at different rates. This could result in excitons formed in the EML often migrating to the vicinity of the hole transport layer and the electron transport layer. To address this, it is important to design high-quality multi-resonance hosts that can balance the migration rate of carriers. Here, we report two newly developed multi-resonance hosts, m-ICzPBI and o-ICzPBI. The hosts contain an indolo[3,2,1-jk]carbazole (ICz) motif, which functionalized as either a donor or an acceptor unit. The hosts exhibit extremely high molecular rigidity and thermal stability. Devices A and B were constructed using FIrpic as a phosphorescent emitter with m-ICzPBI or o-ICzPBI as a host. Device A achieved high maximum values of EQE, PE and CE of 13.4%, 24.8 lm W-1 and 31.6 cd A-1, respectively, and low efficiency roll-off at 5000 cd m-2 of 8.6%, 10.6 lm W-1 and 20.3 cd A-1, respectively.

| S-EPMC10343769 | biostudies-literature

Azaindolo[3,2,1-jk]carbazoles: New Building Blocks for Functional Organic Materials.

Project description:The preparation and characterization of 12 azaindolo[3,2,1-jk]carbazoles is presented. Ring-closing C-H activation allowed for the convenient preparation of six singly and six doubly nitrogen-substituted indolo[3,2,1-jk]carbazole derivatives in which ten of the materials have not been described in the literature before. The detailed photophysical and electrochemical characterization of the developed materials revealed a significant impact of the incorporation of pyridine-like nitrogen into the fully planar indolo[3,2,1-jk]carbazole backbone. Furthermore, the nitrogen position decisively impacted intermolecular hydrogen bonding and thus the solid-state alignment. Ultimately, the versatility of the azaindolo[3,2,1-jk]carbazoles scaffold makes this class of materials an attractive new building block for the design of functional organic materials.

| S-EPMC6491992 | biostudies-literature

Thienopyrrolo[3,2,1-<i>jk</i>]carbazoles: Building Blocks for Functional Organic Materials.

Project description:The facile preparation of three regioisomeric thienopyrrolo[3,2,1-jk]carbazoles applying a convenient C-H activation approach is presented. The incorporation of thiophene into the triarylamine framework significantly impacted the molecular properties in comparison to the analogous indolo[3,2,1-jk]carbazole scaffold. Dependent on the exact substitution pattern, the absorption onsets of the new materials are shifted toward slightly higher wavelengths compared to the analogous indolo[3,2,1-jk]carbazole, whereas the emission maxima of the sulfur derivatives is shifted from 375 to 410 nm. In analogy, the HOMO-LUMO energy gap of the thienopyrrolo[3,2,1-jk]carbazoles is reduced compared to indolo[3,2,1-jk]carbazole. Therefore, the developed thienopyrrolo[3,2,1-jk]carbazoles enrich the family of triarylamine donors and constitute a novel building block for functional organic materials.

| S-EPMC7173703 | biostudies-literature

5,11-Dimethyl-6,12-dimeth-oxy-indolo[3,2-b]carbazole.

Project description:The title compound, C(22)H(20)N(2)O(2), was prepared in a twofold Cadogan cyclization followed by double N-methyl-ation. The crystal structure is characterized by a zigzag arrangement of centrosymmetric mol-ecules. The indolocarbazole framework is essentially planar [maximum deviation = 0.028 (2) Å] and the meth-oxy groups are orthogonal to this plane [C-C-O-C torsion angle = -88.2 (2)°]. The lengths of the C-N bonds are nearly identical and all C-C bonds of the pyrrole subunit are significantly longer than the C-C bonds in the benzene rings.

| S-EPMC3569787 | biostudies-literature

6,12-Bis(hex-yloxy)-5H,11H-indolo[3,2-b]carbazole.

Project description:The title compound, C30H36N2O2, was prepared in a twofold Cadogan cyclization. The mol-ecule is located about a center of inversion. The indolocarbazole skeleton is essentially planar [maximum deviation = 0.028?(2)?Å], the C-N bond lengths are nearly identical and the C-C bond lengths of the pyrrole unit are significantly longer than those of the benzene subunits.

| S-EPMC3588340 | biostudies-literature

Pyridinyl-Carbazole Fragments Containing Host Materials for Efficient Green and Blue Phosphorescent OLEDs.

Project description: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.

| S-EPMC8348521 | biostudies-literature

Molecular Orientations of Delayed Fluorescent Emitters in a Series of Carbazole-Based Host Materials.

Project description:Molecular orientation is one of the most crucial factors to boost the efficiency of organic light-emitting devices. However, active control of molecular orientation of the emitter molecule by the host molecule is rarely realized so far, and the underlying mechanism is under discussion. Here, we systematically investigated the molecular orientations of thermally activated delayed fluorescence (TADF) emitters in a series of carbazole-based host materials. Enhanced horizontal orientation of the TADF emitters was achieved. The degree of enhancement observed was dependent on the host material used. Consequently, our results indicate that π-π stacking, CH/n (n = O, N) weak hydrogen bonds, and multiple CH/π contacts greatly induce horizontal orientation of the TADF emitters in addition to the molecular shape anisotropy. Finally, we fabricated TADF-based organic light-emitting devices with an external quantum efficiency (ηext) of 26% using an emission layer with horizontal orientation ratio (Θ) of 79%, which is higher than that of an almost randomly oriented emission layer with Θ of 62% (ηext = 22%).

| S-EPMC7262557 | biostudies-literature

Topology and Excited State Multiplicity as Controlling Factors in the Carbazole-Photosensitized CPD Formation and Repair.

Project description:Photosensitized thymine<>thymine (Thy<>Thy) formation and repair can be mediated by carbazole (Cbz). The former occurs from the Cbz triplet excited state via energy transfer, while the latter takes place from the singlet excited state via electron transfer. Here, fundamental insight is provided into the role of the topology and excited state multiplicity, as factors governing the balance between both processes. This has been achieved upon designing and synthesizing different isomers of trifunctional systems containing one Cbz and two Thy units covalently linked to the rigid skeleton of the natural deoxycholic acid. The results shown here prove that the Cbz photosensitized dimerization is not counterbalanced by repair when the latter, instead of operating through-space, has to proceed through-bond.

| S-EPMC9447287 | biostudies-literature

Controlling ice formation on gradient wettability surface for high-performance bioinspired materials.

Project description:Ice-templating holds promise to become a powerful technique to construct high-performance bioinspired materials. Both ice nucleation and growth during the freezing process are crucial for the final architecture of the ice-templated material. However, effective ways to control these two very important factors are still lacking. Here, we demonstrate that successive ice nucleation and preferential growth can be realized by introducing a wettability gradient on a cold finger. A bulk porous material with a long-range lamellar pattern was obtained using a linear gradient, yielding a high-performance, bulk nacre-mimetic composite with excellent strength and toughness after infiltration. In addition, cross-aligned and circular lamellar structures can be obtained by freeze-casting on surfaces modified with bilayer linear gradient and radial gradient, respectively, which are impossible to realize with conventional freeze-casting techniques. Our study highlights the potential of harnessing the rich designability of surface wettability patterns to build high-performance bulk materials with bioinspired complex architectures.

| S-EPMC7399483 | biostudies-literature

5',11'-Dihydro-dispiro-[cyclo-hexane-1,6'-indolo[3,2-b]carbazole-12',1''-cyclo-hexa-ne].

Project description:The title compound, C(28)H(30)N(2), is a symmetrical 2:2 product from the condensation of indole and cyclo-hexa-none. It is the only reported 5,11-dihydro-indolo[3,2-b]carbazole compound in which the spiro atoms are quaternary C atoms. Crystals were grown by vapor diffusion in a three-zone electric furnace. The mol-ecule resides on a crystallographic inversion center. The cyclo-hexyl rings are in a slightly distorted chair conformation, whereas the indole units and the spiro-carbons are coplanar within 0.014?Å.

| S-EPMC3254282 | biostudies-literature

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