Some highlights from the article posted by mikeemarc (#29308):
4-stack W-OLED is made by sequentially depositing anode-red (R)-blue (B)-green (G)-blue (B)-cathode on a glass substrate. W-OLED implements color by passing white light created by multiple light-emitting layers through color filters.
In the 4-stack W-OLED, deuterium substitution technology was used in the blue (B) layer and the green (G) layer. Deuterium substitution technology was not applied to the red (R) layer. The microlens array (MLA) applied to the 3rd generation W-OLED was also omitted in the 4-stack W-OLED. MLA is a technology that increases light extraction efficiency.
"We lowered the panel temperature by improving the device structure and power supply system, and energy efficiency is about 20% (based on 65 inches) higher than before."
Some foreign media outlets have reported that a phosphorescent element is applied to one of the two blue (B) layers of LG Display's 4-stack W-OLED, but this is not true. Both blue (B) layers use fluorescent elements. The technology for mass production of blue phosphorescent elements has not yet been developed. The red (R) layer and green (G) layer use phosphorescent elements. In the emitting layer of Samsung Display's QD-OLED, the blue (B) layer also uses fluorescent elements, and the green (G) layer uses phosphorescent elements. The phosphorescent element has an internal luminescence efficiency of 100%, and the fluorescent element has an internal luminescence efficiency of 25%.
Blue has much lower device efficiency than other colors such as red, so both our W-OLED and (Samsung Display) QD-OLED basically use two or more blue layers. Until last year, W-OLED products expressed yellow by mixing red and green between two blue layers. The key to this year’s 4th-generation OLED is that the red and green that were combined in the middle are now placed in separate layers.
I think that the performance improvement from 3,000 nits to 4,000 nits was experienced and understood by consumers through the exhibition (for the press). OLED elements account for a small portion of the overall OLED display cost. When going from a 3-stack to a 4-stack, more physical materials are used, so the material cost increases somewhat, but we have internally worked on cost reduction activities such as operational efficiency in 2024.
Q. I understand that the 4th generation OLED also has a back-emitting structure. Can we expect a front-emitting structure in the future 5th or 6th generation OLED, and can we expect blue phosphorescence to be applied? (The question about blue was NOT answered.) |
