Preparation of Multicolour Solid Fluorescent Carbon Dots for Light-Emitting Diodes Using Phenylethylamine as a Co-Carbonization Agent

Abstract

Carbon dots (CDs), as a new type of photoluminescent nanomaterial, have attracted extensive attention in various fields because of their unique luminescence properties. However, CDs will exhibit fluorescence quenching in the solid state or aggregate state, which limits their application. In this paper, a unique strategy is proposed to regulate solutions to achieve multicolour fluorescence of CDs in the solid state. We report the successful preparation of orange, green and blue solid fluorescent CDs using citric acid, urea and phenylethylamine as precursors and methanol, ethanol and water as solvents, respectively. The solid-state fluorescence of CDs may be caused by the linkage of the phenylethyl structure to the surface of CDs during formation, which effectively disperses the CDs and prevents π–π interactions between graphitized nuclei. Meanwhile, multicolour solid fluorescent CDs are realized by adjusting the solvent in the preparation process. Based on the excellent fluorescence properties of CDs, orange, green and blue light-emitting diodes (LEDs) are prepared. A white LED (WLED) can be obtained by mixing the three colours of solid fluorescent CDs, which shows the application potential of CDs in display lighting equipment.

Carbon Dots: Synthesis, Characterizations, and Recent Advancements in Biomedical, Optoelectronics, Sensing, and Catalysis Applications

“…Light-emitting diodes (LEDs) in the colors orange, green, and blue are made based on the superior fluorescence characteristics of CND. The three colors of solid fluorescent CNDs may be combined to create a white LED (WLED), demonstrating the use of CNDs in display lighting devices . High-quality full-color carbon quantum dots (CQDs) were successfully manufactured by Yuan-Jun Tong et al at previously unheard-of low pressure and temperature (85 °C, 1.88 bar).…”

“…203 A novel approach is put out by Yulong An et al CNDs may be combined to create a white LED (WLED), demonstrating the use of CNDs in display lighting devices. 204 High-quality full-color carbon quantum dots (CQDs) were successfully manufactured by Yuan-Jun Tong et al at previously unheard-of low pressure and temperature (85 °C, 1.88 bar). Simple amine engineering was used to create stable and narrow fluorescent emissions that ranged from blue to green and red light.…”

One-Pot Synthesis of Dual Color-Emitting CDs: Numerical and Experimental Optimization towards White LEDs

“…Furthermore, such CDs need to be uniformly incorporated into solid-state matrices without relevant degradation of their spectroscopic characteristics [ 18 , 19 , 20 ]. In the past few years, synthesis of CDs through solvothermal treatment of various types of molecular carbonaceous precursors has emerged as a very effective approach to obtaining multicolored emissive CDs [ 13 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. Instead, most of the reported methods for fabricating color-converting nanocomposites rely on blending CDs obtained through separate syntheses, having emission in the blue, green and red upon excitation by a primary source [ 13 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ].…”

“…In the past few years, synthesis of CDs through solvothermal treatment of various types of molecular carbonaceous precursors has emerged as a very effective approach to obtaining multicolored emissive CDs [ 13 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. Instead, most of the reported methods for fabricating color-converting nanocomposites rely on blending CDs obtained through separate syntheses, having emission in the blue, green and red upon excitation by a primary source [ 13 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Although these strategies allow fine adjustment of the final CCT and CRI via easy regulation of the fluorophore’s relative concentrations, they necessarily involve multiple steps for the synthesis and purification of individual CDs.…”

Systematic Study of Solid-State Fluorescence and Molecular Packing of Methoxy-trans-Stilbene Derivatives, Exploration of Weak Intermolecular Interactions Based on Hirshfeld Surface Analysis

“…Moreover, solvent interactions or concentration effects do not affect the observations. The efficiency of solid-state fluorescence depends on the combination of nonradiative intramolecular deactivation processes and the arrangement of molecules in the crystal lattice, where the net effect causes either quenching or enhancement of the fluorescence quantum yield compared to that of the solution [ 4 , 5 , 6 , 7 ]. Among the factors resulting from the molecular arrangement in the crystal lattice, which influences the fluorescent properties, the occurrence of hydrogen bonds and π-π stacking interactions can be detected [ 8 ].…”