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- Vol. 01 - White OLED Combining High Efficiency With Long Life
- Performance of Thermal Stability
Research and Development
About
Development of Phosphorescent White OLED
with Extremely High Power Efficiency and Long Lifetime
Tomoyuki Nakayama, Kunimasa Hiyama, Keiichi Furukawa, and Hirofumi Ohtani
Konica Minolta Technology Center, Inc., Display Technology R&D Laboratories,
6. Performance of Thermal Stability
Storage stability is also as important as color stability in practical use. Storage stability about luminance and color measured by the accelerating condition of 85 degrees centigrade are shown in Fig.5. Change of the luminance is only less than 1%, and color change ΔE is also only less than 0.005. In addition, outbreak of dark spot and decrease of emission area was not seen as shown in photographs in Fig.6.
An accelerating condition of 85 degrees centigrade was used. Measurements were done under a constant electric current at room temperature. The current density used was 2.5mA/cm2. Open circles (
) indicate luminance and triangles (
) indicate color shift.
The left is a photograph before a save at 85 degrees centigrade. The right is a photograph after a save of 520 hours at 85 degrees centigrade.
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