Carbon Dots with Blue‐to‐Near‐Infrared Lasing for Colorful Speckle‐Free Laser Imaging and Dynamical Holographic Display

As a new solution-processable laser material, carbon dots (CDs) offer advantages of non-toxicity, low-cost, and high-stability, which are conducive to the sustainable development of miniaturized lasers. Full-color CDs (FC-CDs) with bright-blue, green, yellow, red, deep-red, and near-infrared (NIR) fluorescence are prepared. Their photoluminescence emission ranges from 431 to 714 nm. The FC-CDs show narrow full widths at half maximum in the range of 44-76 nm, with concurrent high radiative transition rates (K_R ) of 0.54-1.74 × 10⁸ s^-1 ; their performance is comparable to that of organic laser dyes, indicating their good gain potential for lasers. Laser pumping of the FC-CDs gives laser outputs at 467.3, 533.5, 577.4, 616.3, 653.5, and 705.1 nm, spanning from blue to NIR region, and covering 140% of the NTSC color gamut. The FC-CDs show high Q-factors (2000-5500), appreciable gain coefficients (9-21.5 cm^-1 ), and better stability (≈100%@4-7 h) than commercial laser dyes. These excellent properties make them suitable for high-quality, colorful, speckle-free laser imaging and dynamic holographic display. The findings will be helpful in promoting the practical applications and development of solution-processable CD-based lasers.