The evolution of next-generation cellular networks is aimed at creating faster, more reliable solutions. Both the next-generation 6G network and the metaverse require high transmission speeds. Visible light communication (VLC) is deemed an important ancillary technology to wireless communication. It has shown potential for a wide range of applications in next-generation communication. Micro light-emitting diodes (μLEDs) are ideal light sources for high-speed VLC, owing to their high modulation bandwidths. In this review, an overview of μLEDs for VLC is presented. Methods to improve the modulation bandwidth are discussed in terms of epitaxy optimization, crystal orientation, and active region structure. Moreover, electroluminescent white LEDs, photoluminescent white LEDs based on phosphor or quantum-dot color conversion, and μLED-based detectors for VLC are introduced. Finally, the latest high-speed VLC applications and the application prospects of VLC in 6G are introduced, including underwater VLC and artificial intelligence-based VLC systems.The evolution of next-generation cellular networks is aimed at creating faster, more reliable solutions. Both the next-generation 6G network and the metaverse require high transmission speeds. Visible light communication (VLC) is deemed an important ancillary technology to wireless communication. It has shown potential for a wide range of applications in next-generation communication. Micro light-emitting diodes (μLEDs) are ideal light sources for high-speed VLC, owing to their high modulation bandwidths. In this review, an overview of μLEDs for VLC is presented. Methods to improve the modulation bandwidth are discussed in terms of epitaxy optimization, crystal orientation, and active region structure. Moreover, electroluminescent white LEDs, photoluminescent white LEDs based on phosphor or quantum-dot color conversion, and μLED-based detectors for VLC are introduced. Finally, the latest high-speed VLC applications and the application prospects of VLC in 6G are introduced, including underwater VLC and artificial intelligence-based VLC systems.

The emission wavelength of InGaN/GaN dot-in-wire LED can be tuned by modifying the nanowire diameter, but it causes mismatched angular distributions between blue, green, and red nanowires because of the excitation of different waveguide modes. Besides, the far-field radiation patterns and light extraction efficiency are typically calculated by center dipoles, which fails to provide accurate results. To address these issues, we first compare the simulation results between central dipole and dipole cloud with experimental data. Next, we calculate and analyze the display metrics for full-color nanowire LEDs by 3D dipole cloud. Finally, we achieve unnoticeable angular color shift within ±20° viewing cone for augmented reality (AR) and virtual reality (VR) displays with an improved light extraction efficiency.The emission wavelength of InGaN/GaN dot-in-wire LED can be tuned by modifying the nanowire diameter, but it causes mismatched angular distributions between blue, green, and red nanowires because of the excitation of different waveguide modes. Besides, the far-field radiation patterns and light extraction efficiency are typically calculated by center dipoles, which fails to provide accurate results. To address these issues, we first compare the simulation results between central dipole and dipole cloud with experimental data. Next, we calculate and analyze the display metrics for full-color nanowire LEDs by 3D dipole cloud. Finally, we achieve unnoticeable angular color shift within ±20° viewing cone for augmented reality (AR) and virtual reality (VR) displays with an improved light extraction efficiency.