Advances in the study of the preparation of native quantum dots for the national nanocenters

As a product of the continuous development and cross-over of two-dimensional material systems and quantum systems, quantum chips have drawn much attention in recent years.Due to their transverse size generally less than 20 nm, quantum chips not only have the intrinsic characteristics of two-dimensional materials, but also have quantum limits Domain and prominent edge effects.

Transition metal disulfides (TMDs) are a class of two-dimensional materials with extraordinary properties and great potential. As the most representative TMDs, molybdenum disulfide (MoS2) and tungsten disulfide (WS2) have been widely studied. Quantum chip preparation is divided into bottom-up and top-down two ways. Bottom-up preparation often requires harsh reaction conditions and complicated post-processing, top-down preparation of the quantum yield obtained from the normal yield In addition, both methods of preparation face the challenge of how to avoid defects and obtain intrinsic quantum sheets.

Zhang Yong, director of the National Nanoscience Center, co-authored the research team of Liu Xinfeng and Gao Peng of Peking University, and invented a new technology that can produce defect-free intrinsic MoS2 and WS2 quantum chips on a large scale. Assisted ball milling, ultrasonic assisted solvent stripping and other measures to produce defect-free intrinsic MoS2 and WS2 quantum sheets at very high yields of 25.5 wt% and 20.1 wt%, respectively.After collecting the quantum dot powder, by means of redispersion The quantum dots can be dispersed in high concentration (20mg / mL) in a variety of solvents.When the 0.1wt% quantum dot is loaded on the PMMA film, the optical properties of the quantum dots can be greatly improved, which is higher than that of the films loaded with nanosheets An order of magnitude.The preparation technology has very good universality, provides a train of thought for large-scale production of two-dimensional quantum sheets.

Relevant research results have been published in Nano Letters on the topic of High-yield production of MoS2 and WS2 quantum sheets from their bulk materials, and the preparation method has been applied for a Chinese invention patent. The research was supported by the National Natural Science Foundation of China, the Chinese Academy of Sciences's Hundred Talents Program, Start-up funds and other funding.

Papers link

MoS2 and WS2 quantum chip preparation mechanism diagram

2016 GoodChinaBrand | ICP: 12011751 | China Exports