ETNews posted an interesting article, claiming that Samsung Display is developing a new TV technology that combines OLED emitters with quantum-dot photo-luminescence materials. The basic idea is to use blue OLED emitters and then convert the blue light to white light using quantum-dots combined with color filters (QDCFs) to add red and green colors.
This seems to be a rather complicated design, but it could be much easier to produce compared to a true RGB OLED TV, as there is no need for precise OLED patterning. This is similar to LG's WRGB OLED TVs which use a white OLED source (made from yellow and blue emitters) and color filters on top.
These QD-OLED TVs will offer similar performance to LG's WRGB OLED TVs, and will be thinner than Samsung's current current QD-LED (LCD) TVs and will offer superior contrast and response times. A main challenge in such a design however, will be the low efficiency - the current fluorescent blue emitters are not very efficient, and adding color filters further reduces the efficiency of the display.
ETNews claims that Samsung already produced 55" and 65" QD-OLED prototypes and demonstrated these (probably in private meetings) during CES 2018. The technology is not yet ready, and Samsung is reportedly facing challenges with blue light leakage through the red and green QDCFs.