There has been a lot of discussion about why Samsung is going for QDOLED technology, given the complications, the technology risk and the amount of money involved. Several times I have found myself thinking "They must know something that we don't". It turns out that they certainly do - as was detailed in an article published yesterday in the prestigious publication, "Nature".
We're planning to publish a more detailed look at the paper once we have had a chance to absorb it (and after the Thanksgiving holiday in the US!). However, I thought I'd take a very high level look at the issue from a commercial point of view (as I'm no chemist. I love listening to someone like Jason Hartlove of Nanosys wax lyrically on the science, but 90% is out of my comfort zone!)
Samsung, of course, is the giant of small OLEDs - it has a completely dominant market share of the market. It had 78% of capacity in 2017 for small OLEDs in 2017 and will still have 38% in 2025, despite Chinese investments, according to DSCC.
On the other hand, Samsung had a huge project to build large OLEDs that was just too technically difficult. At the time, there were several challenges (all as far as I know - let me know if you know differently!):
The firm planned to use LTPS for the backplane. It has never been in production at anything beyond 27" (and mostly much smaller) as far as I know.
There has never been a successful (in volume production) method of depositing the OLED materials on large substrates in individual subpixels). Samsung had a concept known as LITI, using lasers, but in the end it had to use shadow mask methods and these have never been scaled in mass production for OLEDs beyond notebook size. (LG deposits its materials in layers, not in subpixels. Samsung does deposit as subpixels in its small OLEDs)
Blue OLED material lifetimes and efficiency were not good enough. (they have improved, but this remains a major challenge).
There were challenges in encapsulation, although those have been solved for now using inkjet techniques.
However, Samsung has to get out of LCD production because of the unequal competition from Chinese makers that have access to effectively free capital and has said that it will do so by 2025.