Preparation and Properties of Carbon Dot‐Grafted CaAl₁₂O₁₉:Mn⁴⁺ Color‐Tunable Hybrid Phosphor

A series of carbon dots (CDs) grafted CaAl₁₂O₁₉:Mn⁴⁺ (CAO) color‐tunable hybrid phosphors have been synthesized via a facile sol‐gel method. Through the hydrolysis and condensation reactions of the silica precursor, CDs can be incorporated into highly flexible hybrid materials through combining with a CaAl₁₂O₁₉:Mn⁴⁺ phosphor within silica gel networks for the fabrication of flexible displays and multicolor luminescent materials. By tuning the mass ratio of CDs/CAO and by adjusting the excitation wavelength, the color of the luminescence can be systematically tailored from purplish‐red (0.504, 0.250) to greenish‐blue (0.238, 0.192). Furthermore, the temperature‐dependent luminescent properties of the CDs/CAO phosphors makes them suitable as thermometers with a wide linear temperature sensing range from 80 to 300 K.