Electrical properties of dye-doped colour tunable organic light emitting diode

Authors

  • Sirintra Khantham,

    1. College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand
    2. Thailand Center of Excellence in Physics, CHE, 328 Si Ayutthaya Rd., Bangkok 10400, Thailand
    Search for more papers by this author
  • Benchapol Tunhoo,

    Corresponding author
    1. College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand
    2. Thailand Center of Excellence in Physics, CHE, 328 Si Ayutthaya Rd., Bangkok 10400, Thailand
    • College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand.
    Search for more papers by this author
  • Korakot Onlaor,

    1. College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand
    2. Thailand Center of Excellence in Physics, CHE, 328 Si Ayutthaya Rd., Bangkok 10400, Thailand
    Search for more papers by this author
  • Thutiyaporn Thiwawong,

    1. College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand
    2. Thailand Center of Excellence in Physics, CHE, 328 Si Ayutthaya Rd., Bangkok 10400, Thailand
    Search for more papers by this author
  • Jiti Nukeaw

    1. College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand
    2. Thailand Center of Excellence in Physics, CHE, 328 Si Ayutthaya Rd., Bangkok 10400, Thailand
    Search for more papers by this author

Abstract

In this work, we report on the electrical properties of dye-doped colour tunable organic light-emitting diode (OLED). The device structure is glass substrate/indium tin oxide/N,N′-di(naphthalen-1-yl)-N,N′-diphenyl-benzidine (NPB) 30 nm/Alq3:DCM 50 nm/Aluminum (Al) 150 nm where NPB is the hole transport layer. Alq3:DCM is the emitting layer which made of tris(8-hydroxyquinoline) aluminium (Alq3) doped with 4-(Dicyanomethylene)-2-methyl-6-(4-dimethyl-aminostyryl)-4H-pyran (DCM) organic dye. The influence of doping concentration has been investigated by current density–voltage measurement, luminance intensity–voltage characteristic, electroluminescence (EL) and impedance spectroscopy, respectively. The EL spectrum exhibits the shifted of peak position from green to red region. The threshold voltage of the device decreased at the low DCM doping concentration (1 wt.%), in contrast, when the increase in the doping concentrations then the threshold voltage will be increased. The highest luminance intensity and lowest turn-on voltage of OLED can be observed at doping concentration about of 1 wt.% of DCM. The impedance characteristics of the dye-doped OLED can be modelled by simply adopting the conventional equivalent circuit with the simple combination of resistors and capacitors network. © 2012 Canadian Society for Chemical Engineering

Ancillary