Get ready to squint! World's smallest pixel is just 300 nm

How many 1080p screens can you fit on a pinhead? These German physicists reckon about one

Micro-OLED displays with 1080p (1920x1080) resolution have been around for a few years now, but a group of German researchers has taken things to the next level. They've engineered an OLED pixel so small that an entire 1080p display could fit into a single square millimeter, potentially changing the game for wearable displays.

We're talking about an OLED tiny enough that the wavelength of the light it emits is larger than the pixel producing it. In this case, it's a subwavelength pixel measuring just 300 by 300 nanometers that can produce orange light, according to a paper published in Science Advances by physicists from the University of Würzburg. 

And yes, for those wondering, this pushes the limits of classical optics, the university pointed out in its summary of the research, led by professors Jens Pflaum and Bert Hecht. Funnily enough, it didn't take new rules of physics to achieve - just a bit of corner cutting, so to speak, to ensure the nanopixel doesn't self-destruct. 

Miniaturization, Pflaum explained to the university, leaves nanometer-sized pixels with uneven electric fields that concentrate at the corners of the gold antenna forming the OLED's base - the same structure the Würzburg team was working with. In this case, the team was using a small gold cuboid measuring 300 by 300 by 50 nanometers. 

"As with a lightning rod, simply reducing the size of the established OLED concept would cause the currents to emit mainly from the corners of the antenna," Pflaum said in the university's release. "The resulting electric fields would generate such strong forces that the gold atoms becoming mobile would gradually grow into the optically active material." 

Once it did so, the atoms would form filaments that would short circuit the pixel. To address this problem, the team insulated the gold pixel antenna with a ring of hydrogen silsesquioxane laid onto the gold pixel nanoelectrode using electron beam lithography. The end result, the team said, was a ridiculously small, orange light-emitting OLED just as bright as a conventional 5 × 5 micrometers OLED pixel. Hecht noted that this light was stable and functional for two weeks "under ambient conditions." 

In short, there's now a pathway open to some super tiny, super efficient displays that could be housed in devices a lot lighter than a pair of Mark Zuckerberg's bulky Ray-Bans. 

Of course, going from a single nano OLED pixel to a working screen will take some time, and with an efficiency of just one percent, there's still a lot of work to be done. The team is developing more efficient nanopixels able to produce additional colors, but there's no word on how long that'll take, and we didn't hear back from the researchers before publication. 

In the meantime, micro display enthusiasts will have to settle for connecting their systems to this 0.7" 1080p AMOLED display until an even tinier one arrives on the scene out of Würzburg. ®