Highly luminescent carbon nanoparticles as yellow emission conversion phosphors

• We first explored rapid and low-temperature fabrication of CNPs using HMT/glucose mixing solution as precursor.
• The quantum yield of the obtained CNPs is as high as 58.3%.
• Broad yellow emission was both achieved with ultraviolet light or blue light excitation, indicating such CNPs phosphors can be used in fluorescent lamps or white LEDs.

We report the novel synthesis of luminescent carbon nanoparticles (CNPs) and their applications as yellow emission conversion phosphors. CNPs were obtained in a hydrothermal process using hexamethylenetetramine (HMT)/glucose mixed solution as precursor. The mixed glucose is found to facilitate the decomposition of HMT, which leads to rapid and low-temperature growth of CNPs. CNPs (quantum yield exceeding 58%) solutions exhibit strong blue-green emission with ultraviolet light illumination and possess typical excitation-dependent photoluminescence (PL) behavior. CNPs were also coated onto ultraviolet and blue LEDs. Broad yellow emission was both achieved with ultraviolet or blue light excitation, indicating such CNPs phosphors can be used in fluorescent lamps or white LEDs. The nontoxic nature and broad yellow emission indicates potential applications of CNPs for phosphor-based white light-emitting devices.