3 years ago

Near-infrared emission of dinuclear iridium complexes with hole/electron transporting bridging and their monomer in solution-processed organic light-emitting diodes

Near-infrared emission of dinuclear iridium complexes with hole/electron transporting bridging and their monomer in solution-processed organic light-emitting diodes
To obtain efficient near-infrared (NIR) emitting materials, a novel iridium (III) complex based on a triphenylamine functionalized pyridylpyrene ligand, namely, Mono-Ir, as well as its two corresonding dinuclear iridium (III) complexes possessing π-conjugated bridging linkages of hole-transporting carbazole (Caz) unit or electron-transporting 2,5-diphenyl-1,3,4-oxadiazole (OXD) unit, namely D-Ir-Caz and D-Ir-OXD, were successfully synthesized and characterized. Under photo-excitation, similar phosphorescence spectrum were obtained for the three complexes with intense NIR emission peak at approximately 698 nm and emission wavelength ranging from 650 to 900 nm. Also, in their single-emissive-layer OLEDs with a device structure of ITO/PEDOT:PSS/TFB/CBP:PBD:complexes/TmPyPB/Liq/Al, similar NIR electroluminescent (EL) emission peaked at 698 nm with a shoulder at 762 nm were obtained. The Mono-Ir-based device showed an external quantum efficiency (EQE) of 1.29% at low current density of 3.5 mA cm−2, while a relatively lower efficiency of 0.27% for the D-Ir-Caz-based device and 0.41% for the D-Ir-OXD-based device, accompanied with negligible efficiencies roll-off at high current densities were achieved, respectively. The better device performance should be achieved when coupled with electron transporting bridging, especially at high currents.

Publisher URL: www.sciencedirect.com/science

DOI: S0143720817318284

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.