Small MicroLEDs: Challenges and Solutions in AR/VR Device Advanced Technology

Ever wondered why the future of augmented and virtual reality (AR/VR) devices depends on tiny micro-light-emitting diodes (μLEDs) smaller than a speck of dust? Despite their promise of high brightness and low power consumption, these ultra-small μLEDs encounter a significant hurdle: their efficiency drops as they get smaller. This study dives into why this happens by looking at how electrically charged particles, called carriers, move sideways in ion-implanted μLEDs. The implanted area restricts carrier injection and sets the μLED size.Size reduction mirrors what happens with conventional μLEDs—a drop in efficiency. A special telescope analyzed the light distribution to find out how carriers spread within the active region. The spreading length decreased with higher currents, from 11. 2 microns at 1 amperes per square centimeter to 2. 4 microns at 1000 amperes per square centimeter. This tells us the secret behind the size-dependent efficiency loss in μLEDs lies in the sideways movement of carriers.