Full-Color Fluorescence of Carbonization-Triggered Carbon Dots for Multifunctional Light Module: Implications for Plant Lighting

Carbon dots (CDs) are widely used in the field of optoelectronics due to their excellent luminescent properties. However, CDs have difficulty achieving long-wavelength modulation due to their complex structure and unclear luminescence mechanism, which limit their application and development in real-life situations. In this work, we explored the effect of the degree of carbonization on the long-wavelength emission of CDs. In this work, blue, green, and red fluorescent CDs were prepared by a hydrothermal carbonization method using sodium lignosulfonate as a carbon source. The experimental results show that the size and graphitization degree of CDs increase gradually with increasing carbonization time, and the sp 2 structure and graphite N atoms also increase gradually, which causes the fluorescence red shift of CDs, which is verified by chemical simulation calculations. The starch was embedded in CDs to prepare tricolor phosphors, which were applied to full-color light-emitting diodes (LEDs). Finally, the combination of CDs and modules extends the range of applications for which CDs can be used. The prepared multifunctional modules that can be used for multicolor switching can be used not only for plant lighting to promote plant growth but also for indoor lighting. This work has implications for the modulation of long-wavelength emission of CD fluorescence, expanding the practical applications of LEDs prepared from CDs and promoting the development of CDs in the field of optoelectronics.