Samsung Display Announces Development of LEDoS Technology, Targeting AR Device Market

Samsung Display (SDC) has unveiled its vision for Silicon-based LED (LEDoS) technology for Augmented Reality (AR) device displays, projecting that LEDoS technology will evolve from a "blue + quantum dot (QD)" approach to "RGB 3-panel" and "Monolithic 1-panel" methods.

Samsung Display’s Vice President, Huh Jong-moo, presented various LEDoS technologies at a microdisplay conference. A significant feature of LEDoS is the substitution of silicon substrates for glass substrates, with inorganic materials (LEDs) being deposited on the silicon substrates to form Micro LED.

LEDoS is widely regarded as suitable for AR device displays, as AR devices require interaction with reality, such as marking information in the real world through the AR device screen. Based on LED, LEDoS offers advantages in screen brightness in this context.

Specifically, the "blue + QD" method involves forming blue LEDs on a CMOS substrate, followed by color display through a QD color conversion layer. This technique can also incorporate a microlens array (MLA) on top of the QD layer to maximize light emission and enhance brightness. Moreover, MLA technology can be applied to LEDoS through both "RGB 3-panel" and "Monolithic 1-panel" methods.

The "RGB 3-panel" method forms red, green, and blue Micro LEDs on three separate CMOS substrates to produce three panels. This approach requires waveguide technology to guide light in a specific direction to transmit images.

The "Monolithic 1-panel" method involves vertically stacking or horizontally aligning red, green, and blue LEDs on a CMOS substrate to produce a single panel.

Huh Jong-moo noted that while RGB can be formed by depositing on glass or CMOS substrates, LEDs require a high-temperature epitaxial process on wafers to individually create RGB LEDs, which are then integrated onto the CMOS substrates. Whether using three panels or individually patterning RGB LEDs, the technical challenges are substantial, leading to higher product costs and greater difficulty in developing high-resolution panels.

The XR market is still in its early stages, but Huh Jong-moo is optimistic that if XR devices can provide content value, usability, and competitive pricing, the XR market will start to grow and prosper.

Indeed, since the end of 2022, Samsung Display has set a goal to develop "microdisplays of about 1 inch" under the name "Project M." In addition to LEDoS, Silicon-based Organic Light Emitting Diode (OLEDoS) technology is also a flagship microdisplay technology.