Owing to high pixel density and brightness, gallium nitride (GaN) based micro-light-emitting diodes (Micro-LEDs) are considered revolutionary display technology and have important application prospects in the fields of micro-display and virtual display. However, Micro-LEDs with pixel sizes smaller than 10 μm still encounter technical challenges such as sidewall damage and limited light extraction efficiency, resulting in reduced luminous efficiency and severe brightness non-uniformity. Here, we reported high-brightness green Micro-displays with a 5 μm pixel utilizing high-quality GaN-on-Si epilayers. Four-inch wafer-scale uniform green GaN epilayer is first grown on silicon substrate, which possesses a low dislocation density of 5.25 × 10⁸ cm⁻², small wafer bowing of 16.7 μm, and high wavelength uniformity (standard deviation STDEV < 1 nm), scalable to 6-inch sizes. Based on the high-quality GaN epilayers, green Micro-LEDs with 5 μm pixel sizes are designed with vertical non-alignment bonding technology. An atomic sidewall passivation method combined with wet treatment successfully addressed the Micro-LED sidewall damages and steadily produced nano-scale surface textures on the pixel top, which unlocked the internal quantum efficiency of the high-quality green GaN-on-Si epi-wafer. Ultra-high brightness exceeding 10⁷ cd/m² (nits) is thus achieved in the green Micro-LEDs, marking the highest reported results. Furthermore, integration of Micro-LEDs with Si-based CMOS circuits enables the realization of green Micro-LED displays with resolution up to 1080 × 780, realizing high-definition playback of movies and images. This work lays the foundation for the mass production of high-brightness Micro-LED displays on large-size GaN-on-Si epi-wafers.

由于像素密度和亮度高，基于氮化镓 （GaN） 的微型发光二极管 （Micro-LED） 被认为是革命性的显示技术，在微显示和虚拟显示领域具有重要的应用前景。然而，像素尺寸小于 10 μm 的 Micro-LED 仍面临侧壁损坏和光提取效率受限等技术挑战，导致发光效率降低和严重的亮度不均匀性。在这里，我们报道了利用高质量硅基氮化镓外延层的 5 μm 像素的高亮度绿色微型显示器。四英寸晶圆级均匀绿色 GaN 外延层首先在硅衬底上生长，该衬底具有 5.25 × 10^{8 cm-2} 的低位错密度、16.7 μm 的小晶圆弯曲和高波长均匀性（标准偏差 STDEV < 1 nm），可扩展至 6 英寸尺寸。基于高质量的 GaN 外延层，采用垂直非对准键合技术设计了像素尺寸为 5 μm 的绿色 Micro-LED。原子侧壁钝化方法结合湿法处理成功解决了 Micro-LED 侧壁损伤问题，并在像素顶部稳定地产生了纳米级表面纹理，从而释放了高质量绿色硅基氮化镓外延片的内部量子效率。因此，绿色 Micro-LED 实现了超过 10⁷ cd/m² （nits） 的超高亮度，标志着报告的最高结果。此外，Micro-LED 与硅基 CMOS 电路的集成可实现分辨率高达 1080 × 780 的绿色 Micro-LED 显示器，实现电影和图像的高清播放。 这项工作为在大尺寸硅基氮化镓外延片上大规模生产高亮度 Micro-LED 显示器奠定了基础。