Highly Efficient Full-Color Inorganic LEDs on a Single Wafer by Using Multiple Adhesive Bonding

Monolithic integration is a promising way to realize full-color high-resolution displays. However, it is still a challenge to realize a highly efficient full-color light-emitting diode (LED) adopting color conversion layer. In this work, red, green, and blue inorganic LED thin films grown on respective substrates for high-quality epitaxial layers are integrated on a single substrate using a multiple adhesive bonding technique. It is verified that the stacked thin films are structurally stable. After the multiple bonding, respective subpixels are formed by using standard photolithography only without a mass transfer process, showing the possibility of applying them to a high-resolution micro-LED display. Even after the bonding, the device still maintains high efficiency without deteriorating performance. The integrated subpixels are not only independently operated by controlling input power, but the light emission can also cover a wide range of the color space, about 83% compared to Rec.2020 color space.

Automated summary

Monolithic integration of red, green, and blue inorganic LED thin films on a single substrate using multiple adhesive bonding technique demonstrates structurally stable stacked thin films without the need for mass transfer process. The integrated subpixels can be independently operated with high efficiency and cover a wide range of the color space.