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How Samsung's QD-OLED hybrid could take on LG for TV supremacy

Could quantum dots and OLED combine to create the TV of the future?

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Samsung sells LCD-based QLED TVs today, and a new investment means it might sell OLED-based TVs in the future.

Sarah Tew/CNET

There are two basic TV technologies on the market today: LCD and OLED. LCD-based TVs are much more common and popular because they're less expensive and easier to manufacture. OLED TVs have better picture quality but cost more money. LCD TV-makers use a variety of enhancements to improve image quality, one of which is called quantum dots.

Samsung has been selling LCD TVs enhanced by quantum dots for the last few years under the QLED brand, and in CNET's tests they do have improved color compared to other LCD sets. But they still don't match the overall image quality of OLED, mainly because of OLED's incredible contrast and off-angle performance. And at the moment only one company makes big-screen OLED display panels: LG.

But what if you could combine the benefits of quantum dots with the contrast ratios of OLED? It would would create a sort of hybrid TV with, potentially, picture quality better than any current TV. 

Samsung recently announced it's building a factory to do just that:

Samsung Display will invest 13.1 trillion won by 2025 to build "Q1 Line," the world's first QD display mass production line at Asan Campus. The new line is scheduled to start production in 2021 with an initial 30,000 sheets (8.5 generations) and will produce a huge QD display of 65 inches or larger.   

That's an investment of around $11.1 billion. While Samsung calls this "QD display," it isn't electroluminescent, aka "direct view" quantum dots. That technology is still several years away. This is going to be a QD-OLED hybrid.

At the announcement event, South Korean President Moon Jae-in also referenced Samsung's rival LG in regards to Korea's place in world TV production: "It is important to maintain the top spot of the global display market with game-changing technologies," Moon said. "Following LG Display's 3 trillion-won investment in large OLED panel production in July, Samsung Display's latest investment plan brightens prospects further."

Samsung claims it wants to start production in 2021, which might mean we'll see some TVs for the holidays that year. More likely, however, we'll see prototypes at CES 2022.

What does this all mean? Samsung hasn't yet replied to our request for additional information, but Nanosys, a company that makes quantum dots, has shared some details on how the technology will likely work.

How QD-OLED would work

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A simplified diagram of how a QD-OLED hybrid would work. A blue OLED material would create all the blue light, plus the light energy that red and green quantum dots would use to create red and green light.

Samsung

Combining quantum dots and OLED could play to the strengths of both technologies. The idea with any TV is to create red, green and blue light. LED LCDs with quantum dots, like Samsung's current QLED TVs, use blue LEDs and a layer of quantum dots to convert some of that blue into red and green. With the current version of OLED, yellow and blue OLED materials create "white" light. In both cases, color filters let pass only what color is needed for that specific subpixel.  

The idea with a QD-OLED is to simplify these designs into one, by using OLED to create blue light, and then a quantum dot layer to convert some of the blue into red and green.

qdcc-oled

How Nanosys envisions QD-OLED will work. Samsung's version will likely be similar. A blue OLED layer creates blue light, which passes through a quantum dot color conversion ("QDCC") layer that converts some of that blue into red and green. Thanks to how quantum dots work this is significantly more efficient than using color filters.

Nanosys

There are many advantages to this method, in theory. By using only one color or material of OLED, the manufacturing costs go way down since it's easier to build. LG, for instance, uses only two OLED materials, blue and yellow, for every pixel across the entire display. Light-blocking color filters create the green and red. QDs have nearly 100% efficiency, significantly better than filters, so in theory the hybrid TVs will be much brighter. Plus, there's the possibility of even wider color gamuts at all brightness levels.

qd-oled

On the left, the current version of OLED. "White" in LG's case being a combination of blue and yellow OLED materials. On the right, how QD-OLED will likely work, using only blue OLED, and then converting some of that with red and green quantum dots.

Nanosys

Because each pixel can be shut off, these hybrid TVs will also have the incredible contrast ratios that OLED is known for.

Since blue OLED materials still age faster than red and green, having the entire panel one color means the TV ages more evenly with no color shift. Keeping that aging to a minimum, and thereby having a TV that doesn't seem dim after a few years, is one of the key manufacturing issues. This is especially true in this HDR era of extreme brightness levels.

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A very, very closeup view of a QDCC layer. Behind this could be either blue LEDs, or blue OLED. Either way, the color that comes out is red, green and blue.

Nanosys

While this new Samsung plant is focusing on TV-size displays, the technology could work in phone-sized displays as well. Since Samsung doesn't seem to have any issue making excellent small OLEDs, I'd be surprised if it's in any rush to upset that market with something as advanced as this. Also, Samsung's phone-sized OLEDs use red, green and blue OLEDs compared to LG's blue-yellow. Samsung tried to make RGB OLED TVs and just couldn't make them profitable.

Into the future

It's possible, maybe even likely, that LG is working on a similar QD-OLED hybrid. Right now it's not saying (we asked). It is, however, the logical next step for OLED before whatever next generation of TV tech arrives. 

And what might that be? Well, the quantum dot folks seem to think direct-view quantum dot displays are just a few years off. These electroluminescent quantum dots, or ELQD, would have all the benefits of OLED, all the benefits of QD and none of the issues of LCD or the wear and longevity concerns of OLED. A very promising tech indeed.

direct-view-qd

The ultimate quantum dot display. No more LCD at all, just direct view, electroluminescent quantum dots. This is essentially how OLED works, but instead of organic light emitting materials, it's quantum dots.

Nanosys

Then there's the question of what Samsung will call this new QD-OLED technology, since it's already branded its current TVs as "QLED." It's a safe bet it won't be calling them OLED anything, since that's LG's "thing" and Samsung is already trying to use the fear of burn-in to trash-talk the technology. It's worth noting the Samsung division that sells TVs, Samsung Electronics, is different from Samsung Display, the division that will be making these QD-OLEDs.

The other new TV tech on the horizon from Samsung and others is MicroLED. This has many of the same benefits as the QD-OLED hybrid, but doesn't muck around with those pesky organics. That's even farther in the future, however, likely somewhere in time between QD-OLED and direct-view quantum dot displays. Oh, and MicroLEDs use quantum dots too. They're a fascinating technology with uses far beyond TV screens.


Got a question for Geoff? First, check out all the other articles he's written on topics like why you shouldn't buy expensive HDMI cablesTV resolutions explainedhow HDR works and more.

Still have a question? Tweet at him @TechWriterGeoff, then check out his travel photography on Instagram. He also thinks you should check out his best-selling sci-fi novel and its sequel