Picosun ALD enhances micro-LED efficiency

Picosun Atomic Layer Deposition (ALD) has played a vital role in enhancing electro-optical characteristics of micro-LEDs in research done by National Yang Ming Chiao Tung University (NYCU) in Taiwan.

The usage of dielectric films as a passivation material is a popular technique to suppress dangling bonds as well as to improve output power and external quantum efficiency in LEDs. The study conducted at NYCU compared III-Nitride micro-LEDs of different sizes with and without ALD Al2O3 passivation. The results showed external quantum efficiency enhancement of 70% for 5 µm × 5 µm micro-LEDs and 60% for 10 µm ×10 µm micro-LEDs when using ALD Al2O3 passivation.

In addition, to achieve full color display, an inkjet printing to pattern quantum dots automatically has been developed at NYCU. The solution can considerably improve the precision of color pixels and satisfy the high-resolution requirements. Picosun ALD passivation technology was successfully used for preventing the quantum dots from photo-oxidation and degradation. After a 500 hours environmental reliability test, the color gamut remained at excellent level.