Surface-Modified Carbon Dots with Improved Photoluminescence Quantum Yield for Color Conversion in White-Light-Emitting Diodes

Abstract

Surface modification of p-phenylenediamine-derived carbon dots using 4-morpholinoaniline with an electron-donating and rigid structure followed by purification using silica gel column chromatography increased the photoluminescence quantum yield from 28.3 to 41.8% in chloroform. The improved photoluminescence quantum yield was observed for the surface modification by postaddition of the surface modifier after the formation of the π-conjugated structure of the carbon dot core but was not observed for the carbon dots prepared from a mixture of p-phenylenediamine and 4-morpholinoaniline. The finding of this work gives us an idea to design carbon dots with high photoluminescence quantum yield for application of color conversion in white-light-emitting diodes.

Functional carbon dots derived from biomass and plastic wastes

“…CDs typically have a spherical shape with particle sizes <10 nm and primarily are comprised of amorphous carbon and nanocrystalline regions of sp 2 hybridized graphitic carbon. These nanomaterials exhibit several desirable properties, including stable photoluminescence, [3][4][5][6] low toxicity, 7 good biocompatibility 8,9 and environmental compatibility, 10 ease of surface modification 11 and stable chemical properties, 12 making them useful for various applications such as fluorescent labeling, [13][14][15][16] bio-bacterial chemicals, 17 photocatalysis, [18][19][20] and flame retardation. 21 The preparation methods of CDs can be divided into top-down and bottom-up approaches, with the primary difference being the sources of CDs.…”

Zinc-Reduced Carbon Quantum Dots as Color-Conversion Materials in Blue Light-Emitting Diodes

“…As shown in Figure S1, both CQDs and Zn-CQDs showed CH 2 bending vibrations (∼1410 cm −1 ). 19 In the FTIR spectra of CQDs, the O−H vibrations are present at ∼2500−3300 cm −1 and ∼940 cm −1 . C�O vibration is present at ∼1678 cm −1 and stretching vibration of the carboxyl group is present at ∼1579 cm −1 .…”

Ratiometric fluorescence detection of doxorubicin by R-CQDs based on the inner filter effect and fluorescence resonance energy transfer

“…6 The combination of CQDs with organic dyes, 7 metal heteroatoms, 8 and metal-organic complexes 9 has greatly extended the range of light ground absorption and its fluorescence emission while increasing the quantum yield of CQDs, so that CQDs show great potential application values. 10 In addition, the combination of CQDs and some functional materials to meet some special application requirements is also very positive to expand the application of CQDs in the field of analysis and sensing. 11 Doxorubicin (DOX) is an effective anti-cancer drug that inhibits tumor growth and spreads well.…”