Phosphorescent Dye-Doped Organic Light Emitting Diodes (OLEDs) for Electronic Displays

Technology #15091

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Researchers
Franky So
Ying Chen
Jong Hyun Kim
Rui Liu
Managed By
Richard Croley
Assistant Director 352-392-8929

Dye-Doped Hole Transport Layer Increases Efficiency, Stability and Longevity

This organic phosphorescent dye used as a charge transport layer improves the efficiency of organic light emitting diodes (OLEDs). In recent years, science and industry have taken great interest in OLEDs because of their high efficiency. The creation of a hole transporting layer is a significant reason for this increased efficiency, while also giving the diode the ability to balance charges. The hole transporting layer is commonly composed of di-4-tolylaminophenyl cyclohexane (TAPC). However, TAPC hole transporting layers have short lifetimes. Researchers at the University of Florida have developed a phosphorescent-dye doped hole transporting layer structure that will give OLEDs improved operational stability with high current efficiency. These phosphorescent dyes will also significantly improve the lifetimes of the OLEDs.

Application

Doping the hole transport layer of organic light emitting diodes (OLEDs) with phosphorescent dyes increases efficiency, stability, and longevity for electronic displays

Advantages

  • Enhances the OLEDs ability to balance charges, increasing efficiency
  • Limits the accumulation of charges between hole transport layer and emitting layer interphase, extending the lifetime

Technology

Organic phosphorescent dyes have good electron and hole mobility. Doping the hole transport layer with organic phosphorescent dyes increases the ability of OLEDs to transport charges. Hole transport layers are commonly composed of hole transport electron blocking material, such as TAPC. TAPC-based OLEDs degrade due to hole accumulation between the TAPC and emitting layer interface. This causes a voltage rise and luminance decay during device operation. The phosphorescent dye eliminates the hole injection barriers, significantly improving the lifetime of the diode. The host material is not limited to hole dominant materials or materials with high hole mobility. Doping electron dominant materials will also produce efficient and stable OLEDs.