1. Ammonium hydroxide modulated synthesis of high-quality fluorescent carbon dots for white LEDs with excellent color rendering properties
- Author
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Yajing Chang, Dabin Yu, Hui Wang, Guopeng Li, Nan Yuan, Yang Jiang, Zhifeng Zhu, and Shengda Wang
- Subjects
Materials science ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Gamut ,law ,General Materials Science ,Electrical and Electronic Engineering ,Aqueous solution ,business.industry ,Mechanical Engineering ,General Chemistry ,021001 nanoscience & nanotechnology ,Fluorescence ,0104 chemical sciences ,Color rendering index ,Ammonium hydroxide ,chemistry ,Mechanics of Materials ,Optoelectronics ,0210 nano-technology ,business ,Luminescence ,Carbon ,Light-emitting diode - Abstract
A novel type of aqueous fluorescent carbon dot (CD) was synthesized using citric acid as the only carbon source via an ammonium hydroxide modulated method, providing a blue color gamut. The amino group is considered to be the key factor in the high fluorescence of CDs and a model is established to investigate the mechanism of fluorescence. In addition, white light-emitting diodes (WLEDs) are fabricated by utilizing the prepared CDs and rare earth luminescent materials (SrSi2O2N2:Eu and Sr2Si5N8:Eu) as color conversion layers and UV-LED chips as the excitation light source. The WLEDs produce bright white light with attractive color rendering properties including a color rendering index of up to 95.1, a CIE coordinate of (0.33, 0.37), and a T c of 5447 K under a 100 mA driven current, indicating that the CDs are promising in the field of optoelectronic devices.
- Published
- 2016