To make QD-OLED panel more efficient
Samsung Display was researching phosphorescent blue OLED material to apply on quantum dot (QD)-OLED panels, according to a South Korean professor.
Kyung Hee University professor Kwon Jang-hyuk told audiences at SID 2022 Review Symposium held in Seoul on Wednesday said it seemed the South Korean display panel maker was prioritizing applying phosphorescent blue OLED material on its advanced TV panel.
Currently, OLED panels used in TVs and smartphones use phosphorescent OLED materials with 100% internal luminance efficiency for the red and green.
However, for the blue, fluorescent materials with only around 25% luminance efficiency are used.
Display makers and material companies such as UDC are researching phosphorescent OLED materials to extend the life span of OLED panels.
Samsung Display’s current QD-OLED panel uses fluorescent blue OLED material and green phosphorescent OLED material as the emission layer.
The layers are in what the company calls a four tandem structure, where there are three blue layers and one green layer. This is the same for its 34, 55 and 65-inch panels that are used for monitors and TVs.
Using phosphorescent blue OLED material will allow Samsung Display to reduce the number of blue layers to one.
The company was also researching ways for a three tandem structure where there are two blue layers.
In February, Samsung Display published a paper on Nature Photonics called: Exceptionally stable blue phosphorescent organic light-emitting diode.
Professor Kwon noted that the research was done over a year ago and Samsung Display likely had made a process on developing phosphorescent blue OLED material.
Samsung Display was aiming to make visible results of the research within the year, Kwon claimed.
Phosphorescent OLED material can use energy from both singlet excitation and triplet excitation, which accounts for 25% and 75% of the energies used by the material, allowing for 100% luminance efficiency.
In contrast, phosphorescent OLED material can only use energy from singlet excitation, hence the luminance efficiency of 25% and why Samsung Display needs three layers of blue on its QD-OLED panel.
US OLED firm UDC had said back in February that it was aiming to commercialize phosphorescent blue OLED material in 2024.