Development of Phosphorescent White OLED
with Extremely High Power Efficiency and Long Lifetime

• Abstract
• Introduction
• Target of Power Efficiency
• Experimental
• Performance of Efficiency and Lifetime
• Performance of Color Stability
• Performance of Thermal Stability
• Summary and Conclusion Remarks
• References

3. Experimental

Organic layers were evaporated on ITO anode on a glass substrate. Al was used to the cathode. As carrier injection and transport layers across the emission layers, we used materials which had high carrier mobility, and optimized the constitution of layers to decrease the drive voltage. In the electron injection and transport layer, a material developed by Konica Minolta Technology Center, Inc. was used. The emission layers included blue, yellow-green and red phosphorescent dopants and a host material. Blue dopant and host material was developed by Konica Minolta Technology Center, Inc. Yellow-green and red dopants were obtained from Universal Display Corporation.

Glass cap encapslation was done by using UV hardening glue in pure dried N2. Absorbents were included in the device. Emission area was 4mm² or 15cm². Performance of both device is nearly the same.

IVL characteristics and emission spectra were measured by spectrophotometer Konica Minolta Sensing CS1000. In calculation of power efficiency, revision of light population on the device surface was done. Lifetime is defined by time before reaching the luminance reduction by half from the initial luminance under consecutive drive conditions. Storage stability was evaluated in accelerating condition of 85 degrees centigrade.

• Contact