1.6-Inch Transparent Micro-Display with Pixel Circuit Integrated microLED Chip Array by Misalignment-Free Transfer.

Area of Science:

• Materials Science
• Electrical Engineering
• Optoelectronics

Background:

• Micro light-emitting diode (µLED) displays face integration challenges with active-matrix backplanes.
• Mass transfer technology is advancing, paving the way for next-generation µLED displays.

Purpose of the Study:

• To innovate µLED display technology by developing pixel circuit-integrated micro-LEDs (PIMLEDs).
• To demonstrate the integration of PIMLEDs onto a transparent glass substrate for novel display applications.

Main Methods:

• Fabrication of PIMLEDs comprising low-temperature poly-silicon transistors and Gallium Nitride (GaN) µLEDs.
• Design of square-shaped PIMLEDs with four-fold rotational symmetry for improved process margin and bonding alignment.
• Development of concentric circular pixel electrodes on the substrate to facilitate massive, misalignment-free fluidic transfer.

Main Results:

• Successful integration of PIMLEDs onto a transparent glass substrate.
• Demonstration of a 96 × 96 PIMLED display.
• Vertically integrated pixels exhibited consistent optical and electrical properties across different arrangements.
• The design ensured compatibility with fluidic transfer and eliminated angular misalignment during wafer bonding.

Conclusions:

• PIMLEDs offer a viable solution for reliable µLED integration.
• This technology enables the development of transparent and form-factor-free µLED displays.
• The demonstrated approach paves the way for advanced display applications.