Small
·
2017
·Vol. 13
·期 26
·1700075
·
IF 8.643
Jiangling He,Youling He,Yonghao Chen,Bingfu Lei,Jianle Zhuang,Yong Xiao,Yeru Liang,Mingtao Zheng,Haoran Zhang,Yingliang Liu
Stable solid-state red fluorescence from organosilane-functionalized carbon dots (CDs) with sizes around 3 nm is reported for the first time. Meanwhile, a novel method is also first reported for the efficient construction of dual-fluorescence morphologies. The quantum yield of these solid-state CDs and their aqueous solution is 9.60 and 50.7%, respectively. The fluorescence lifetime is 4.82 ns for solid-state CDs, and 15.57 ns for their aqueous solution. These CDs are detailedly studied how they can exhibit obvious photoluminescence overcoming the self-quenching in solid state. Luminescent materials are constructed with dual fluorescence based on as-prepared single emissive CDs (red emission) and nonfluorescence media (starch, Al 2 O 3 , and RnOCH 3 COONa), with the characteristic peaks located at nearly 440 and 600 nm. Tunable photoluminescence can be successfully achieved by tuning the mass ratio of CDs to solid matrix (such as starch). These constructed dual-fluorescence CDs/starch composites can also be applied in white light-emitting diodes with UV chips (395 nm), and oxygen sensing.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Chemistry
·
2025
·
IF 6.7
Zeyu Wang,Qing Yao,Jindou Shi,Zheyuan Da,Junnan Wang,Ahmed Allam,Haifa E. Alfassam,Xiangming Li,Jinyou Shao,Minqiang Wang
Multicolor solid-state carbon dots (MSCDs) with superior photothermal stability and tunable fluorescence exhibit significant potential for applications in light-emitting diodes (LEDs) and optoelectronic devices. However, the development of a facile and efficient synthetic method using simple raw materials remains a challenge. In this study, blue (B), green (G), and red (R) emissive carbon dots (B-CDs, G-CDs, and R-CDs) are synthesized by varying pre-treatment methods and raw material ratios, using 1-(1-Naphthyl)ethylamine (1-NEA) as the carbon source and boric acid (BA) as the matrix. B-CDs, prepared via freeze-drying pre-treatment in a nitrogen (N 2 ) protective atmosphere, exhibits the smallest particle size and the largest emission bandgap. Conversely, G-CDs and R-CDs display larger particle sizes, with R-CDs having the smallest emission bandgap due to differing raw material ratios that introduced distinct surface state defects. These variations in emission bandgaps result in diverse fluorescence emissions under ultraviolet (UV) light excitation. Leveraging the excellent luminescent properties, white LEDs (W-LEDs) are fabricated by combining and coating the CDs onto a 400 nm LED chip. The resulting W-LEDs demonstrate outstanding photothermal stability and a high color rendering index (CRI) of 90–93 during prolonged operation. This work provides valuable insights for the application of MSCDs in W-LED technology.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Fan Liu,Shuhong Xu,Pengfei Xia,Hongyu Yang,Ziting Qian,Yuan Jiang,Zhuyuan Wang,Dayan Ban,Chunlei Wang
In this work, fluorescent solid carbon dots (CDs) welcome a new member, namely anhydride-terminated CDs, which have a photoluminescence quantum yield (PLQY) of 28% for orange-emitted CDs at 580 nm in powder form. For the first time, we revealed that the electronic coupling of the functional groups should be a crucial factor affecting the optical properties of solid CDs. Due to the negligible hydrogen bonding interaction between the anhydride groups, the electronic coupling of excitons between neighboring anhydride groups is weak, leading to a high PLQY of 28% and an immobile emission peak at 580 nm in solid state. Anhydride-terminated CDs can be partly converted into carboxyl-terminated CDs after dispersion in ethanol. However, the strong electronic coupling of carboxyl groups at high concentration generates the stacking mode of J-aggregates, giving rise to a red-shifted emission from 450 to 515 nm as well as quenched fluorescence in solid state. In comparison, a useful blue emission for solid-state CDs occurs from low sp2 hybridized carbon atoms, which possess weak electronic coupling and a stationary emission band at 450 nm in both solution and solid state. By adjusting the feed ratio of the reactants, the relevant intensities between the emission from low sp2 hybridized carbon atoms at 450 nm and the emission from anhydride groups at 580 nm can be controlled. As a result, single-component anhydride-terminated CD powder with tunable emission color from orange to white light can be achieved. As-prepared anhydride-terminated CDs can be used for fabricating light-emitting diodes (LEDs), white LEDs, and luminescent solar concentrators (LSCs).
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）