LEDs Enter the Nanoscale, But efficiency hurdles challenge the smallest LEDs yet
Summary
IEEE Spectrum reports progress and challenges in nanoscale LEDs (nanoLEDs), highlighting prototypes below 500 nm and demonstrations at 100 nm or smaller. Efficiency remains a major bottleneck, with external quantum efficiencies in the 5–13% range for nanoLEDs, far below typical millimeter-scale LEDs. The article covers approaches from bottom-up hexagonal pyramids to OLED and perovskite nanoLEDs and discusses potential applications in VR, smart glasses, metasurfaces, and on-chip photonics for AI data centers, while noting diffraction limits and manufacturing hurdles ahead.