Blue-light-excited cyan-emitting carbon dots towards healthier white light-emitting diodes: a perspective

White light-emitting diodes (WLEDs) now dominate the lighting and display industries because of their energy efficiency and long lifespan. However, conventional WLEDs are typically constructed by combining blue InGaN LED chips (440-460 nm) with yellow-emitting phosphors (520-700 nm). This design suffers from two critical limitations. The first is a 'blue overshoot' that poses significant health risks. The second is a 'cyan gap' in the region of 470-520 nm that compromises color rendering fidelity. In this perspective, we highlight the transformative potential of blue-light-excited cyan-emitting carbon dots (CDs) as a sustainable and high-performance solution to address these challenges. CDs offer tunable photoluminescence, high quantum yields, and eco-friendly synthesis. These attributes make them superior to rare-earth-based phosphors and toxic perovskite nanocrystals. We summarize the latest research progress in synthesizing cyan-emitting CDs and their integration into polymer or Ormosil matrices. These integrations demonstrate significant reductions in blue-light hazard and simultaneous enhancements in color rendering index values. We finally outline key future directions, including material optimization, scalable synthesis, mechanistic exploration, and expanded applications, to unlock the full potential of cyan-emitting CDs for next-generation, healthier, and more sustainable WLED technologies.