As most regular AVS Forum readers know, quantum dots are becoming increasingly important in the world of flat-panel TVs. Nanosys is at the forefront of QD development, as the company clearly demonstrated at the Display Week 2018 conference this week.
To reiterate the basics, quantum dots (QDs) are microscopic spheres of semiconductor material that absorb blue light and emit light at a longer wavelength, depending on their size. Such QDs are called photo-emissive. In current-generation QD-based LCD TVs, the backlight consists of blue LEDs and a plastic film impregnated with randomly distributed QDs of two different sizes—one size emits green light and the other emits red light. The red and green light combines with unabsorbed blue light from the LEDs, forming white light that passes through the LCD layer and red, green, and blue color filters to form the final image. This application is called quantum-dot enhancement film (QDEF).
In addition, QDs can be deposited directly on super-thin sheets of glass, which is known as quantum dots on glass (QDOG). In the next phase of development, QDs will be used to replace the color filters used in LCD and even OLED TVs; this is called quantum-dot color-filter replacement (QDCFR). The ultimate application for TVs is electrically stimulating QDs to emit light directly in a process known as quantum-dot electro-luminescence (QDEL). You can read much more about all these technologies in my coverage from CES last January.
Nanosys was demonstrating QDCFR and QDEL applications is highly prototype form at Display Week 2018. (Samsung Display had a QDOG TV in its booth, which I will discuss in a separate article.) The company also had a couple of product demos in its booth. On one wall, there was a 65″ Vizio P-Series Quantum, seen in the photo above, which is a P-Series with QDEF that should be shipping this summer. (Some say it’s an update of the Reference Series, which also used QDEF.) It was playing an internal demo loop in store-demo mode—in other words, in vivid mode!
With 192 FALD zones, the P-Series Quantum is said to achieve a peak brightness of over 2000 nits and over 98% of the DCI-P3 color gamut. Amazingly, the 65-incher will carry a list price of only $2200! Of course, vivid mode was more like a cartoon, but I can’t wait to see what it can do after being fully calibrated in a more controlled environment.
On another wall, there was an LG OLED next to a Samsung Q9F. Both were 65″ screens in their out-of-the-box movie/cinema mode playing the same content. The Q9F uses QDEF in a full-array local-dimming (FALD) configuration, and as you might imagine, it was a lot brighter than the OLED. Also, it exhibited more shadow detail, though it looked somewhat undersaturated compared with the OLED. Also, the off-axis performance of the QLED was not as good as the OLED. However, the “bug” in the upper right corner of the image was burned into the OLED, which was running continuously for eight hours a day, but not the QLED. I also say some less-obvious image retention elsewhere on the OLED that was not evident on the QLED.
Nanosys put an LG OLED next to a Samsung QLED for comparison. Both were in their out-of-the-box movie/cinema mode.
The signage next to each set included some of the results of measurements performed by rtings.com. The Q9F exhibited a peak brightness up to 3400 nits for five seconds in a 10% window and a full-screen peak brightness of 700 nits. The color gamut was at least 99% of DCI-P3 and 78% of BT.2020, and the screen reflectivity is 1.5%. By contrast, the OLED’s peak brightness in a 10% window was 733 nits with a full-screen peak brightness of 137 nits. It achieved over 97% coverage of DCI-P3 and 74% of BT.2020. Screen reflectivity was also 1.5%.
Quantum dots hold great promise for the future of flat-panel TVs and even microLED displays, and I look forward to bringing you all the latest QD news as I learn it.