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Gram‐Scale Synthesis of Highly Efficient Rare‐Earth‐Element‐Free Red/Green/Blue Solid‐State Bandgap Fluorescent Carbon Quantum Rings for White Light‐Emitting Diodes
Author(s) -
Meng Ting,
Wang Zifei,
Yuan Ting,
Li Xiaohong,
Li Yunchao,
Zhang Yang,
Fan Louzhen
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202103361
Subject(s) - phosphor , light emitting diode , fluorescence , quantum efficiency , quantum yield , green light , carbon fibers , diode , materials science , band gap , solid state lighting , optoelectronics , chemistry , photochemistry , optics , blue light , physics , composite number , composite material
The negative impact of rare‐earth elements (REEs) on the environment, limited supply and high cost prompt the need for REE‐free phosphor‐converted white light‐emitting diodes (LEDs). Here, we report the gram‐scale synthesis of red/green/blue solid‐state bandgap fluorescent carbon quantum rings (R/G/B‐SBF‐CQRs) with high quantum yields up to 30–46 %. This was achieved using cyano‐group‐bearing p‐phenyldiacetonitrile as precursor and forming carbon quantum rings of different diameters through the linkage of curved carbon quantum ribbons of different lengths. The results show the role of cyano groups in inducing the curvature of the carbon quantum ribbons for CQR formation and emission of stable solid‐state bandgap fluorescence. R/G/B‐SBF‐CQRs‐phosphor‐based LEDs emitted warm white light with low CCT (3576 K), high CRI (96.6), and high luminous efficiency (48.7 lm W −1 ), comparable to REE‐phosphor‐based LEDs.