Design and fabrication of an ultra-high definition and ultra-thin color conversion layer for micro-LED displays

Abstract

Micro-LED, known for its excellent performance in terms of color, contrast, resolution, response time, lifespan, and energy consumption, is considered the indispensable display technology for the next generation, particularly in the field of augmented reality (AR)/virtual reality (VR) displays. However, the further development of AR/VR still faces challenges in maintaining high image quality and relying excessively on the mass transfer technique to manufacture micro-LED screens, which results in increased costs and time consumption. To address these two significant challenges, we propose the following solutions. Firstly, we employ well-developed photolithography techniques to fabricate color conversion microarrays. This method allows for the simultaneous fabrication of millions or even tens of millions of pixels in a single process with a high yield. Under blue light illumination, it can accurately display the three primary colors. Importantly, this approach enables the creation of any desired pixel geometry simply by modifying the photomask design. Secondly, for pixel miniaturization, we simultaneously reduce the aspect ratio of the pixels. This approach realizes a more robust pixel structure, minimizing color crosstalk and improving the scalability of the display. To further optimize the effect of reducing the aspect ratio of the pixels, we introduce a nanomaterial, zinc oxide (ZnO), which exhibits a thermal conductivity four times higher than that of SiO2 and TiO2 nanoparticles. By incorporating ZnO, we can increase the efficiency of color conversion, enhance the emitted light brightness, reduce blue light leakage, and improve the heat resistance of the color conversion microarrays, ultimately achieving exceptionally high display quality.