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

Abstract

Abstract 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 × 10 8 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.