1-nm-thick epitaxial AlN passivation for highly efficient flexible InGaN red micro-LEDs

Highly efficient, ultrahigh-density inorganic micro-LED displays are gaining a strong position in the market for use in augmented reality glasses. When applied to electronic contact lenses with an eye-adaptive form factor, the micro-LED displays evolve into next generation augmented reality viewers. Here, we report 1-nm-thick epitaxial AlN passivation for 1.5-μm-diameter InGaN red micro-LEDs with high external quantum efficiency of 6.5% at the peak wavelength of 649 nm. The flexible form factor of the red micro-LEDs is achieved through the development of a near-complete device transfer. By overcoming the existing bottlenecks of red spectral efficiency and form factor of inorganic micro-LEDs, we believe this will pave the way for another revolution in the augmented reality and metaverse industries.