Recently, Qusongnan Research Group of Changchun Institute of Optical Precision Machinery and Physics, Chinese Academy of Sciences, and Guo Ruiqian of Fudan University, have put forward a new convenient and quick method to prepare pure carbon nanodot phosphors with high fluorescence quantum efficiency, which fluoresce in solid state using hydrogen peroxide solution of suitable concentration. The light quenched carbon nanodots were treated by surface oxidation to achieve high efficient luminescence in the solid state of carbon nanodots.
同时利用该碳纳米点荧光粉较短荧光寿命的特点，与郭睿倩课题组合作，首次将所研制的碳纳米点荧光粉应用于可见光通讯器件。该工作对于研究解决碳纳米点的固态猝灭以及推动碳纳米点在照明及可见光通讯器件中的应用具有重要意义。该成果发表在国际期刊Advanced Science上(Adv. Sci. 2018, 1800369)，第一作者为在读博士生周正杰，复旦大学田鹏飞为共同第一作者，通讯作者为曲松楠和郭睿倩。并申请了一项国家发明专利，已受理。
At the same time, taking advantage of the short fluorescence lifetime of the carbon nano-dot phosphor, the carbon nano-dot phosphor was firstly applied to visible light communication devices in cooperation with Guo Ruiqian's project. This work is of great significance for solving the solid-state quenching of carbon nanodots and promoting the application of carbon nanodots in lighting and visible light communication devices. The results were published in the International Journal Advanced Science (Adv. Sci. 2018, 1800369). The first author was a doctoral student, Zhou Zhengjie. Tian Pengfei of Fudan University was the co-first author. The correspondent authors were Qu Songnan and Guo Ruiqian. And has applied for a national invention patent, has been accepted.
Qusongnan's research group used hydrogen peroxide solution to oxidize carbon nanodots synthesized by microwave irradiation with citric acid and urea as raw materials. This method is different from the reported method of doping carbon nanodots into substrates such as PVA or inorganic salts. The treated carbon nanodots obtain wide band gap. The surface energy level structure inhibits the radiation-free transition of the surface state of the carbon nanodots in the aggregated state, and achieves the yellow-green carbon nanodots with 25% fluorescence quantum efficiency in the solid state.
以所研制的碳纳米点荧光粉作为颜色转换层，通过调节碳点荧光粉的比例，制备出不同色温的白光LEDs。所研制的碳点荧光寿命只有几个纳秒(~ 6ns)，将其作为光转换层，制备可见光通信领域器件，国际上首次实现了带宽为285MHz、信号传输速率为435 Mbps的基于碳纳米点的可见光通信。
White LEDs with different color temperatures were prepared by adjusting the proportion of carbon nanodot phosphors. The fluorescence lifetime of the carbon dots is only a few nanoseconds (~6ns). Using the carbon nanodots as the optical conversion layer, the devices in the field of visible light communication are fabricated.
此外，研究人员也将传统的量子点应用于制备高效发光粉，并将其应用于白光照明以及通讯中，显色指数可以达到90.3，而光通讯速率可以达到42 MHz。该成果发表在国际期刊ACS Applied Materials & Interfaces上(ACS Appl. Mater. Interfaces 2018, 10, 27160-27170)，第一作者为助理研究员周鼎，通讯作者为曲松楠和郭睿倩。
In addition, the researchers have also applied traditional quantum dots to the preparation of high-efficiency phosphors, and applied them to white light illumination and communication, the color index can reach 90.3, and the optical communication rate can reach 42 MHz. The results were published in the International Journal ACS Applied Materials & Interfaces (ACS Appl. Mater. Interfaces 2018, 10, 27160-27170). The first author was assistant researcher Zhou Ding, and the correspondent authors were Qu Songnan and Guo Ruiqian.
The above work is supported by Changguang-Fudan Cooperation Fund Project, Jilin Provincial Young and Middle-aged Science and Technology Innovation Leader and Team Project, Jilin Provincial Science and Technology Department Natural Science Foundation and so on.