Samsung's New Quantum Dots Serve Up Some Tasty TV Colors

Can an LCD TV outshine OLED? It can if it uses quantum dots.
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The television business is enjoying a platinum age. I don't mean the content, although that's great, too. I'm talking about the hardware. Everywhere you look, manufacturers are placing bets on different technologies they insist will provide the ultimate picture. With 4K resolution, OLED panels, HDR video, and quantum dots hitting mainstream sets, you don't lack for options.

Right now, LG's amazing OLED sets are widely considered the sets to beat. No LCD panel can match their contrast, because every pixel on an OLED screen can be individually controlled. Ink-black pixels cozy up alongside retina-searing colors with pin-sharp distinction. But Samsung and Sony claim their high-end LCD panels already beat OLED, especially if HDR video is your thing. Sony uses sophisticated image processing, crazy-bright panels, and a fine-grained dimming system to deliver a tantalizing picture.

As for Samsung, well, the Korean giant says the future lies with magical nanocrystals called quantum dots in its new line of Q-Series televisions.

Full Metal Jacket

As the name suggests, quantum dots are so small they make the width of an eyelash seem enormous. If you want to go deep on the tech, read my thorough primer on quantum dots. Here are the basics: When an LED backlight hits a quantum dot, it glows. The size of the dot dictates the color---the biggest, at 5.5 nanometers, handle pure reds, smaller dots handle pure green, and the LED backlights handle the blues.

In Samsung's new sets, the quantum dots are arranged in a film that fills the screen. Once the backlight activates them, their light passes through the filters that render the colors you see watching Legion. This improves efficiency---instead of having to divide white light, which represents all the wavelengths of light, into precise colors, the filters in a quantum-dot set work with pristine hues. No light is wasted, resulting in brighter, more accurate colors.

Samsung also claims its revamped dots are cadmium-free, an important environmental benefit. Cadmium-based quantum dots may be able to produce a wider color gamut and improved energy efficiency, but cadmium is a toxic material.

Granted, the first few generations of quantum dot TVs looked more like neon signs, with colors you might call too punchy. Reds and greens in particular were prone to oversaturation. What's more, excessive heat, humidity, and oxidation could over time snuff out the dots' glow. Samsung worked with quantum dot companies to revise the tech in the new sets, placing each dot in a protective metal jacket. Each dot now has a metal core, helping improve stability.

That could potentially make these new TVs better long-term performers than OLED sets. In fact, future quantum-dot sets could become more like OLED panels in terms of their underlying structure. Those quantum dots could end up replacing an LCD TV's backlight system altogether, emitting their own light and offering OLED levels of pixel-by-pixel control.

"Compared to AMOLED, quantum dot is much more stable and has longer life span, because quantum dots are inorganic," says Claire Wen, principal research analyst at Gartner. "Quantum dot has potential to replace LED and become a real light source. The future of quantum-dot TV will have a similar display structure to AMOLED."1

Wen says an OLED-like quantum-dot set is likely years down the line; it's a concept purely in the research and development phase at the moment. For now, Samsung's QLED TVs are simply LCD TVs with an additional layer of color-enhancing nanocrystals. And the boost in efficiency doesn't just enhance these sets' color capabilities. There's a trickle-down effect with the improvements, which translates to better black levels and off-angle viewing, as well.

"The fact that they're brighter, more powerful, and much more focused allows you to add more layers without impacting the color volume or off-angle viewing," says Louis Masses, director of communications at Samsung. "Normally, if you put another layer on the panel, it dims everything. You lose color, you lose brightness. But here, the brightness and the efficiency allows you to put on a layer that helps improve black levels."

To be sure, the Q-Series panels I saw at CES earlier this year provided a richer, more vibrant, and more nuanced picture than their predecessors---at least with the eye-candy demo content companies always show at CES. More impressive, it provided greater detail and richer color at high brightness levels than the LG OLED next to it. Samsung says you can credit color volume for that.

Samsung
Pump Up the (Color) Volume

Imagine a red light bulb on a dimmer. At 20 percent brightness, the bulb casts a pleasant, warm glow. Jack it up to full brightness, and it hurts your eyes. The light in those scenarios may look like different colors, but only the luminance changes.

According to Samsung, the new QLED sets will be able to show the same color no matter the brightness level. Quantum dots and sophisticated tone-mapping and tuning let the Q-Series sets produce a wide range of accurate colors at any luminance level. And these TVs can get seriously bright: 2,000 nits, nearly three times brighter than an iPhone and twice as bright as last year's SUHD sets.

A wider color gamut is common among modern televisions, especially those made for HDR video. Showing forest green at full crank, sky blue at dimmed levels, and millions of shades in between is particularly important for HDR. Although color, contrast, and detail are different aspects of picture quality, granular gradients enhance them all. If you can see a million or so shades of yellow, a banana is going to look more nuanced, more lifelike, more appealing. OLED holds its own with HDR, but only to a point---even though they can achieve perfect blacks, the screens offer half the luminance of a modern LCD set. If you're watching in a bright room and have to crank up the brightness on on OLED, your picture quality may suffer.

“With OLED, they need to make a choice between an accurate color and increasing the brightness,” says Samsung quality assurance manager Chris Andrade. “Brightness only moves it toward the white. So these subtle changes from the colors to white isn’t there. It just kinda goes from full color to white, with less in between.”

At this point, the best quantum dot tech is limited to Samsung's flagship sets, which start at $2,800 and top out at 20 grand. But you don't need much imagination to see prices coming down, as an LCD panel with a sheet of quantum dots generally costs less to produce than an OLED panel. And prices invariably fall as technology moves further into the mainstream. Until then, quantum dots command a premium for their color-volume capabilities.

1UPDATE 3/15/2017 10:00 a.m. ET: This story has been updated to include commentary by Gartner research analyst Claire Wen.