Vertically Stacked MicroLEDs Will Help Us To Create Highest-Ever Pixel Density

Stacking light-emitting diodes instead of placing them side by side could enable fully immersive virtual reality displays and higher-resolution digital screens.

Take apart your laptop screen, and at its heart you’ll find a plate patterned with pixels of red, green, and blue LEDs, arranged end to end like a meticulous Lite Brite display. When electrically powered, the LEDs together can produce every shade in the rainbow to generate full-color displays. Over the years, the size of individual pixels has shrunk, enabling many more of them to be packed into devices to produce sharper, higher-resolution digital displays.

MicroLEDs With Highest-Ever Pixel Density

As detailed in the newly published study in Nature(Opens in a new window), the technology developed at MIT is essentially a better, less wasteful way to make microLEDs(Opens in a new window). The research was led by Jeehwan Kim, an engineering professor specializing in fabricating ultrathin, high-performance membranes. The team used past work on 2D membrane materials to manufacture membranes of red, green, and blue sub-pixels. They peeled the membranes away from the rigid base layers and stacked them on top of each other, creating vertically full-color pixels just 4 micrometers wide.

“This is the smallest MicroLED pixel, and the highest pixel density reported in the journals,” says Jeehwan Kim. These color stacks are just the first step — the team did show that by altering the input voltage, they were able to produce multiple colors in each stacked pixel. However, we would still need a system to control 25 million separate LEDs. Developing that active matrix is something Kim’s group will work on in the future.

This research was supported, in part, by the U.S. National Science Foundation, the U.S. Defense Advanced Research Projects Agency (DARPA), the U.S. Air Force Research Laboratory, the U.S. Department of Energy, LG Electronics, Rohm Semiconductor, the French National Research Agency, and the National Research Foundation in Korea.

Source: https://news.mit.edu/