Recently, the Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology Research Fellow Xue-Feng Yu and Shenzhen University Professor Zhang Han team cooperation in the preparation of black phosphoric quantum dots and ultrafast photonics applications made new progress, the paper entitled "Solvothermal Synthesis and Ultrafast Photonics of Black Phosphorus Quantum Dots "was published in a cover article on the Advanced Optical Materials (DOI: 10.1002 / adom.201600214), the flagship journal in the field of optics written by Wiley, and featured in Watson's Materials Views China.
Since 2014, black phosphorus has gained widespread scientific attention due to its excellent properties and is considered as a two-dimensional atomic material comparable to graphene. Better than graphene, the bandgap of black phosphorus is regulated by the number of layers and absorbs wavelengths from the visible to the infrared range of communication. In addition, black phosphorus is a direct bandgap semiconductor that converts electronic signals into optical signals. Black phosphorous quantum dots are a new form of black phosphorus material. Due to the quantum confinement effect and edge effect, black phosphorous quantum dots are expected to have more excellent photoelectric properties than black phosphor materials. However, research on optoelectronics and ultrafast photonics for black phosphorous quantum dots has not yet been conducted.
Xu Yanhua and Wang Zhiteng, members of the research group, successfully prepared a kind of ultra-small black phosphor quantum dots by solvothermal method, and revealed the nonlinear optical properties of black phosphorous quantum dot material for the first time and successfully applied it in the ultra-fast laser technology. The group successfully prepared black-phosphorus quantum dots with a lateral size of about 2 nm from a black body material by a solvothermal method. The method not only can obtain black phosphorus quantum dots with uniform size, but also can realize large-scale preparation and expand the application of black phosphorous quantum dots in the photoelectric field. In addition, the research group also revealed that the black phosphorous quantum dots have more excellent saturation absorption characteristics than the black phosphorus nanoplates, and the modulation depth is up to about 30%, and the saturation intensity is in the order of GW / cm2. The black phosphorous quantum dots as saturable absorber for the mode-locked laser, in the communication band can produce ultrashort pulse. The research results show that due to its own quantum confinement effect, black phosphorous quantum dots have great potential in the application of ultrafast photonics and are expected to develop into a new kind of optical functional material.
The research has been funded by the National Natural Science Foundation, Shenzhen Peacock team, Shenzhen Branch of the basic layout and other projects funded.