Minute-level synthesis of tunable carbon dots-based phosphorescence materials for information encryption and light-emitting diodes

The emergence of carbon dots has broadened the design and application of new room-temperature phosphorescence materials, but the mass production of long-lived color-tunable carbon dots-based phosphorescence materials (CDPMs) is still hindered by solvent dependence and time-consuming. In this work, a minute-level solid-phase synthesis strategy was proposed for the preparation of a series of CDPMs through pyrolyzing the mixture of boric acid and pimelic acid. By tuning the mass ratio of boric acid and pimelic acid, CDPMs with different room-temperature phosphorescence characterises can be obtained within 7 min. Preferably, the CDPMs-60 synthesized from the mass ratio of boric acid and pimelic acid of 60:1 exhibits a long afterglow length up to 10 s and has obvious phosphorescence chromatic aberrations following excitation at 254 and 365 nm, and phosphorescence lifetimes of CDPMs-60 in the blue and green band can reach 1030 ms and 555 ms, respectively. The CDPMs were further successfully applied for the information encryption and fabricating light emitting diodes based on their simple synthesis process, exceptional optical properties and low-toxicity. This study may provide a valuable reference for the facile synthesis and suitable commercial application of room temperature phosphorescence materials.