How Electro Quantum Dots Might Crush OLED In 4K TVs & Other Devices
Stephan Jukic – December 19, 2017
If there’s one company in the display technology market that should really know its stuff when it comes to quantum dot technology, it’s Nanosys. With over 60 different quantum-dot enabled products on the market and numerous aspects of their technology also present in Samsung’s newest and most impressive QLED 4K HDR televisions, the people at Nanosys are experts when it comes to next-generation display technologies.
Now, this same company is working to make the relatively new and constantly developing technology of quantum dots into something that not only creates better picture quality than ever before seen in TV and other displays, but also into a razor-thin and highly affordable means of pulling this off.
Before we go further though, a quick explanation of what quantum dots are is in order here. For starters, we have QD technology on the consumer market as it stands today. This is what’s now mainly found in Samsung’s 4K HDR TVs from the last couple years and consists essentially of extremely thin filter sheets impregnated with quantum dot nano-crystals which have been applied between the backlight and the display surface of these televisions. As the light from the LEDs behind the display hits these filters (each filter being filled with different sized crystals which emit different colors when hit by light), they convert that light into vibrant, rich high dynamic range colors for the content being displayed. This is what the quantum dot technology of Nanosys delivers right now for the 4K QD displays of today, most notably in the Samsung QLED TV lineup.
What quantum dots are supposed to eventually do though, at least within a few years’ time, is something much more refined. This future of quantum dot displays is what Nanosys is aiming to make reality and it’s what the company (and its partners) hope to see compete with OLED technology such as that found in LG TVs for sheer picture quality and luminance precision.
This future vision of quantum dots means taking them away from the photoluminescence that they currently have (sheets of QD crystals glowing when hit by light from an external LED backlight) and creating electroluminescent quantum dots at the sub-pixel level. This next generation technology would mean tiny quantum dot crystals inside individual sub-pixels within a 4K TV’s pixel array being charged by electrical current to create distinct patterns of extremely refined color and light. In other words, goodbye LED backlights and hello extremely thin QD displays.
Nanosys calls this technology Electro Luminescent Quantum Dot display (ELQD) and it believes that their development will completely disrupt the current television display industry, in which OLED dominates as far as sheer advancement goes.
These new ELQD displays will in fact work a bit like OLED screens in that they won’t require a backlight of any kind but they’ll create a further advantage due to their superior color palette creation ability –to a degree even higher than that achievable by OLED. At the same time, because each QD subpixel inside such screens will be capable of individual activation/deactivation, ELQD screens will deliver the same perfect blacks, pixel-perfect local dimming and wide viewing angles as those achieved by OLED screens today. Another benefit of such pixel luminance efficiency would be lower overall power consumption, since relatively inefficient, broadly luminous LED backlights can (literally) be removed from the picture.
According to Jeff Yurek, Director of Marketing and Investor Relations at Nanosys, this new technology isn’t too far off for the consumer market:
“We expect to see these displays in the three to five year timeframe. We think that quantum dots have the potential to deliver on the promise of OLED.”
OLED technology is of course already delivering something very similar to ELQD displays of the type being worked on by Nanosys. With OLED, individual Organic light emitting diode (OLEDs) inside a TV screen are charged with electrical current to create light that can be turned on or off at the single pixel level. Color filters inside each OLED pixel then create vibrant color patterns. Thus OLEDs too are capable of perfect black levels and pixel-precise dimming of scenes on a display. More importantly still, OLED screens are already here and being used in a growing part of the 4K TV display (and smartphone screen) market. Additionally, while they’re expensive, they’re also getting more affordable as their quality improves. ELQD technology on the other hand is still in its developmental form, without a working consumer screen in sight.
This isn’t deterring Nanosys and its partners however. The company is arguing that their ELQD technology will deliver superior results when it does come out and even the current limited form of QD crystals as they’re found in today’s Samsung HDR TVs does indicate this: Right now, quantum dot material can create superb color accuracy via the individual crystals in the filters we described above. Most importantly, crucial blue light emission performance by quantum dots is nearly perfect. On both of these fronts, OLED in its current form doesn’t quite compete. Today’s latest Samsung QLED TVs and LG’s best OLED TVs in fact bear this out in one notable way: The QLEDs we’ve reviewed deliver minorly but measurably wider wide color gamut coverage and color accuracy than their OLED counterparts (though the OLEDs beat them in most other key respects).
Furthermore, OLED displays, due to the organic nature of their pixel particles are notably weaker performers when it comes to handling moisture. The inorganic crystals of both current QD crystal filters and near future Electro luminescent QD pixel crystals will not have this same limitation, possibly making them much better choices for any display that’s likely to be exposed to rain or other water sources –like a smartphone screen or an outdoor commercial display for example.
Where all of these competitive issues between OLED and electro luminescent quantum dots could really come to a head is in the area of printed, ultra-thin display surfaces, or “active surfaces” as Nanosys itself is calling them. This has also been a developmental promise of OLED technology for a few years now and LG has even unveiled a few prototype screens in which they showcased just how thin OLED display can be made. ELQD screens are supposed to eventually pull off the same feat and Nanosys (like LG) wants to take this technology to a place that goes beyond mere TV displays. According to Yurek,
“Printed quantum dots can really change how we think about our relationship with technology. We are thinking a lot about moving away from a device-centric world to a world of ‘Active Surfaces.’ These surfaces are interactive; they can display information or disappear into a home’s décor or even clothing. They need to be bright, power efficient, sensor-enabled, and rugged.”
Due to the superior ruggedness and color performance that ELQD particularly offers over OLED, achieving these printed screens could give LG’s rival technology a serious run for its money.
However cost remains a huge obstacle. While Nanosys claims to already be able to create inkjet printable quantum dot display surfaces and has even demonstrated this technology to research organizations, the price of doing so is nowhere near commercially viable. The company is thus aiming for further refinement of both quality and cost. “If we can get the cost of making a display down to $100 per square meter, which is basically the same cost as printing a high-resolution poster or printing a T-shirt, then displays could be everywhere,” According to Russell Kempt, VP of sales and marketing at Nanosys. He also claimed that due to its inherent benefits, quantum dot technology is the only way by which this could be done effectively for numerous commercial applications.
Nanosys further claims that all of its current ELQD display work is already being done via printing techniques, regardless of whether the resulting technology is used for the next generations of 4K HDR TV screens or other even more radical applications. OLED for its part is still stuck inside hard display surfaces even though it’s already on the existing consumer market.
Of course, all of the above predictions are just that, predictions, and by a company that’s naturally enough eager to promote its own technology as much as it can. What we can say however is that even with their existing consumer market applications, quantum dot crystals inside filter screens on 4K TV displays have indeed shown themselves to be subtly fantastic performers. And if Nanosys or some other company can indeed cheaply create the paper-thin pure ELQD crystal displays they’re trying to make printable, what we’ve seen so far of QD technology bodes well for claims of ELQD crushing the competition with OLED.
We’ll see what the next three years reveal. LG also has the same time-frame to pull out its own surprise improvements for organic light emitting diodes.