Luminous Junction

Smaller than a speck of dust, this 15-micrometer blue GaN microLED is enclosed by microscopic mirrors that confine and direct its light. By shaping photons with precision, we can create brighter, more energy-efficient displays and faster optical links—technologies that connect and inform our world.

This image captures a 15×15 micrometer blue gallium nitride (GaN) microLED operating under electrical injection. An indium gallium nitride (InGaN) active region generates light at the InGaN/GaN p–n junction through radiative recombination. The device is laterally enclosed by distributed Bragg reflectors (DBRs)—multilayer dielectric mirrors engineered to reflect specific wavelengths—providing optical confinement that enhances light extraction and promotes directional emission. By controlling photon confinement at the microscale, this architecture improves performance beyond conventional planar LEDs, achieving up to 46% higher efficiency and 30% greater emission directivity. The photograph was taken in a dark laboratory environment to highlight the blue electroluminescent glow.

List of all that contributed: Roark Chao, Matt Perko