This Prototype Next-Gen MicroLED Is So Cool It’s Ultraviolet (Literally)
In a dark corner Nanosisnumber here in CES 2025 A tiny, watch-sized prototype was unveiled in Las Vegas. At first glance, it didn’t seem like anything special. It was certainly bright and definitely colorful. The watch band was fake, and it was all built into a box that no doubt helped it function in some way. Even when using a jewelry loupe, there were no outward signs that this is one of the most exciting next-generation display technologies. And yet, it was.
This new one MicroLED goes further at the narrow end of the electromagnetic spectrum than competing models by incorporating four UV LEDs per pixel. In contrast, most LED displays on the market today use some version of a blue LED, as well as red and green quantum dots, to create the red, green, and blue colors needed to create an image. Many other displays use phosphors instead of quantum dots, and some use red, green and blue LEDs.
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If this seems strange, that’s because it is. Plus, as you’ll see, it’s extremely clever. This could even bring down the exorbitant cost of MicroLED displays. Here’s what I learned.
UV LED
Different ways to create a MicroLED display with their respective theoretical pros and cons: On the left – just red, green and blue LEDs. In the middle, blue LEDs emit blue light and excite red and green quantum dots. Right: UV LEDs excite red, green and blue quantum dots. The fourth subpixel is a spare one that helps increase productivity.
First of all, and this was also one of my questions: yes, it is safe. You may have read or heard stories over the past few years where industrial UV lighting has been misused. resulting in damage to the skin and eyes. One of the incredible things about quantum dots is that they convert light of different wavelengths almost perfectly. What little UV remains after most of it is converted by QD to some other color is blocked by the display glass and filter.
There are many benefits to using UV LEDs in a MicroLED display, although they may not be as world-changing as adding quantum dots for OLED or a completely new technology, e.g. nanoLED. This mainly concerns production. MicroLED is one of the newer display technologies, and although it shows promise, it is currently quite difficult to produce. This is one of the reasons why MicroLED displays are so expensive.
When you strip away all the details, a typical MicroLED display is essentially made up of millions of red, green and blue LEDs. Three of them are connected together to form each pixel. Without going too deep, let’s just state the obvious that this is difficult to do. The use of different materials for red, green, and blue LEDs poses certain manufacturing challenges. Problems that using all blue LEDs and adding red and green quantum dots helps partially solve.
The use of UV LEDs takes this one step further. Instead of blue LEDs producing blue light and exciting the red and green QDs, UV light excites the red, green and blue QDs. So each subpixel is the same, just with a different QD view on top. This reduces complexity and theoretically increases yield and thereby reduces production costs. Blue quantum dots are not used as often as red and green ones. The beauty of quantum dots is that it is relatively easy to make them in different sizes, which determines the wavelength (color) they emit. At least in theory, this is simpler than using different LED materials for different subpixel colors. Using UV LEDs comes with its own challenges, but according to UV LED companies like Applied materialsthey are potentially easier to overcome.
Another interesting aspect of this method, at least in its current implementation, is the use of four subpixels instead of three. Due to the relatively high likelihood of dead pixels occurring on any MicroLED display, having a “spare” subpixel that can be used in case one of the red, green or blue subpixels fails can potentially improve yield. During the production process, a dead subpixel may be detected, and any subpixel color that does not work will be painted with a splash of that color. Although this fourth subpixel will increase the overall cost of this aspect of production by approximately 33%, the researchers estimate that it will increase yield enough to be more than worthwhile.
This diagram shows the various steps involved in creating MicroLED displays using UV LEDs. The UV LEDs are mounted on the backplane, four for each pixel, and each has its own “bucket” in which to store the quantum dot material. The inkjet printer places the specified material into a bucket. As accurate as it may be, a little “ink” spills out of the right bucket(s). When this subpixel is turned on, the ultraviolet light created seals the ink in place (also a). The surface is washed to remove spilled paint (b). The process is repeated for green and blue (see). If during this process the computer detects that one of the subpixels is not being activated, a fourth spare subpixel is called into action, receiving the ink color of the dead subpixel (g). In the final step (h), the entire block is covered and secured for further fabrication and assembly.
Another potential benefit to the manufacturing process is the ability to self-cure. Some manufacturers would like to use inkjet printing for small MicroLED displays because of the potential cost benefits. This method works on large displays, but MicroLED is micro.
Using a different CT “ink” formula, the color can be applied to the substrate, cured by its own LED as it emits UV light, and then any spillover of that CT ink color onto an adjacent subpixel can be washed off before the next color is applied to the subpixel (see diagram above ).
This way, each subpixel only has a QD for its color, even if the inkjet itself is not completely accurate, improving color accuracy and productivity. Something about the effectiveness of the treatment of the pixel itself pleases my brain.
Display
The UV MicroLED prototype created by CTC looks like a smartwatch. It has 300 dpi.
Which brings us back to Las Vegas and that bright, tiny display. As you can probably tell from the images, this is a mockup of a smartwatch display. With up to 1000 nits of brightness, it was bright enough in a dark room. CTC, the manufacturer and part of the Foxconn group, estimates that it could produce 3,000 nits at full production.
Why, you ask, would you need a smartwatch with 3,000 nits of brightness if you’re not trying to signal a passing spaceship? To shine in your eyes. One of the most potential applications for MicroLED is in AR and VR headsets, where tiny, efficient, extremely high-resolution displays are vital. It’s like your TV – it doesn’t always produce maximum brightness. Having such brightness potential opens up a wider range of possibilities.
Future displays
Still in the prototype stage, the production display will be brighter and could potentially be used in other devices such as AR/VR headsets and others.
The question always comes up: “When will this come out?” It’s hard to answer other than “not right now.” MicroLED in general and UV MicroLED in particular are in the early stages of their development. There are MicroLED displays on the market, but it is clear that many companies want to see many more MicroLED displays on the market. The trend is to move away from LCD and OLED entirely, but then again, I’ve been writing about the death of LCD for over a decade now, so who knows. We’ll likely see more of these devices later this year and certainly at CES next year.
In addition to highlighting sound and display technologies, Jeff conducts photo tours cool museums and locations around the world, including nuclear submarines, aircraft carriers, medieval castlesepic Trips of 10,000 miles and much more.
Also check Budget travel for dummieshis guide and his bestselling science fiction novel about city-sized submarines. You can follow him Instagram And YouTube.
2025-01-09 21:36:00