Fivefold increase in emission efficiency of gaN micro LEDs at low current density

Micro LED displays that use micro LEDs with a size of approximately 10 µm arranged at high density are attracting much attention.

However, the emission efficiency of conventional micro LEDs drops rapidly as the LED size decreases, especially in the low current density region (< 20 A/cm²) that is important for display operation. This has made it a challenge to realize high-efficiency, high-brightness, high-resolution micro LED displays.

The researchers have developed technology for increasing the efficiency of GaN (gallium nitride) micro LEDs, in collaboration with Tohoku University.

Micro LED displays with micro LEDs arranged at high density is expected as high-efficiency, high-brightness, high-resolution displays for next-generation wearable information terminals. However, conventional fabrication methods result in large processing damage on the LED side surfaces, so there was the major issue that the emission efficiency drops significantly when the LED size is reduced. The researchers fabricated GaN micro LEDs using neutral-beam etching technology that is known to have extremely low processing damage, and realized GaN micro LEDs with almost no drop in emission efficiency even when the LED size is reduced to 6 μm.

Provided by Advanced Industrial Science and Technology