40‐3: Distinguished Paper: Realization of Ultra‐High Efficient Fluorescent Blue OLED

Abstract

The bilayer structure for an emitting layer (EML) was developed to improve performances of a fluorescence blue organic light emitting diode. By functionally separating the EML into the charge recombination and the Triplet‐Triplet Fusion (TTF) zone, we successfully suppressed the quenching of triplet excitons by excess carriers to make more TTF efficient and the local degradation within the EML to make the lifetime longer. In the bottom emission device with the bilayer EML, 12% of external quantum efficiency (EQE) and 450 hours of LT95 were achieved. Furthermore, we achieved over 14% of EQE by optimizing the material combinations.

25‐2: Subpixel Optimization in AMOLED Displays by Self‐assembled Patterning of a Secondary Cathode

“…Although phosphorescent emitters have been successfully applied in the red and green pixels for majority of the AMOLED products, blue fluorescent emitters are still being used. [1] This results in a relatively lower device efficiency of blue than the other two colors. It is also well known that the blue OLEDs have a much lower lifetime than red and green in almost all the commercial products.…”