An international collaboration between several universities around the world has led to an innovation in LEDs that could potentially result in a giant leap forward when it comes to increasing the resolution on TV screens and mobile devices. For the first time ever, a single LED can now change colour all by itself.
The current design and chemical makeup of LEDs limit the technology to producing light in just a single colour. “But Andrew, what about my colour-changing LED smart bulbs,” you’re probably asking. Those actually rely on a cluster of LEDs inside that each produce either red, green, or blue light. When their individual intensities are adjusted, the colours that each light produces mix to produce an overall shade of light.
LED-backlit LCD TVs work in a similar fashion, but to produce one-coloured pixel, three filtered LEDs are required. Even the next big breakthrough in flatscreen TV technology, MicroLEDs, require a trio of ultra-tiny light-producing diodes to create a single pixel, which limits how many can be squeezed into a given area, and resolution.
In a paper recently published to the ACS Photonics Journal, researchers from Lehigh University and West Chester University in Pennsylvania, Osaka University in Japan, and the University of Amsterdam, detail a new approach to making LEDs that uses a rare earth ion called Europium that when paired with Gallium Nitride (an alternative to silicon that’s now showing up in electronics other than LEDs, like Anker’s impossibly tiny PowerPort Atom PD 1 laptop charger) allows the LED’s colour to be adjusted on the fly.
The secret sauce is how power is used to excite the Europium and Gallium Nitride-different ratios and intensities of current can be selectively applied to produce the emission of three primary colours: red, blue, and green.
Using this approach, LED lightbulbs with specific colour temperatures could be produced and sold at much cheaper price points since the colours from multiple tint-specific LEDs don’t have to be mixed. The technology could yield similar benefits for TVs and the screens that end up in mobile devices. Instead of three LEDs (red, green, and blue) needed to generate every pixel, a single Europium-based LED could do the job. Even more exciting than cheaper price tags is the fact that replacing three LEDs with just one could result in a display with three times the resolution.
Your eyes probably wouldn’t be able to discern that many pixels on a smartphone screen, but in smaller displays, like those used in the viewfinders of digital cameras, a significant step in resolution would be a noticeable improvement.