Figure 1. Chemical structure of the dendrimer DOT-p-DPP
Figure 2. Absorption spectrum of a compound that selectively separates semiconducting SWCNTs using dendritic DPP compounds (left) and comparison of the ability of two compounds with linear conjugated polymer PFO to separate SWCNTs
Figure 3. Simulation results of the dendrimer 6T-p-DPP coated single-wall carbon nanotube interaction
Figure 4. Properties of Bottom-gate Transistor Devices Prepared Using 6T-p-DPP / SWCNT Composite Thin-Film Transistor Performance (Left), Different Batch, Single-walled Carbon Nanotube inks Stored at Different Times (right)
Single-walled carbon nanotubes (SWCNTs) have excellent charge transport properties, good solution processing and high flexibility, excellent mechanical properties, high thermal conductivity, excellent mechanical stability and chemical stability. In electronic devices and optoelectronics The devices are widely used, such as transparent conductive film electrodes, thin film transistors, logic circuits, flexible wearable electronic devices, chemical and biological sensors, supercapacitors and solar cells, etc. The thin film transistors prepared by using SWCNTs as an active layer material have excellent electrical properties, Feature size smaller, good stability, faster heat dissipation, higher operating frequency, showing excellent device performance and great potential for application development.
At present, commercially available SWCNTs obtained by high-volume preparative methods are all mixtures of m-SWCNTs and s-SWCNTs with different chirality and tube diameters. By means of physicochemical methods, large-scale selective enrichment of large-diameter semiconductors Single-walled carbon nanotubes are the most effective way to achieve high-performance electronic devices and optoelectronic devices performance.Conjugated polymer coating is a more effective method for the selective separation of semiconductor single-walled carbon nanotubes.Chinese Academy of Sciences Suzhou Nanchang Institute of Nanotechnology and nano-bionic Ma Chang research team and Zhao Jianwen research team to design and synthesis of a series of highly efficient separation of high purity semiconductor single-walled carbon nanotubes nonlinear polymer PDPPb5T, and the use of isolated ink to prepare the performance Excellent transistor devices. Relevant findings are published on Nanoscale and Small.
Due to the polymer's molecular polydispersity and unclear molecular structure, and the molecular weight of the polymer has a great influence on the dispersion and separation of single-walled carbon nanotubes, the selective separation of single-walled carbon nanotubes in device applications is easy Batch differences, to a certain extent, limited its practical application.Organic small molecules do not exist poor reproducibility between batches, but small organic molecules molecular weight, small organic molecules and single-walled carbon nanotubes π-π interaction is weak, leading to the poor storage stability of single-walled carbon nanotube ink with small organic molecules dispersed.In order to achieve the stable dispersion of single-walled carbon nanotubes, it is often necessary to use a large amount of dispersant, while a large amount of dispersant The introduction of the follow-up device performance has an impact.
Recently, Ma Chang research team and Zhao Jian-wen research team further use of controlled synthesis methods, the preparation of the synthesis of both polymer high separation efficiency and small repeatability of small batch of peripheral functionalized modified dendrimeric conjugated compounds (Figure 1), and the selective separation of SWCNTs from these dendrimers has been studied.The results show that compounds with three-dimensional dendrites have stronger SWCNT dispersibility than the linear compounds (Figure 2) A number of functional units in the periphery of the dendrimer can be obtained to obtain stronger intermolecular interaction ability (Figure 3). The semiconducting single-walled carbon nanotube ink separated by the dendrimer and the printed carbon nanotube thin-film transistor are printed The hole mobility of up to 57 cm2 V-1 s-1 was achieved with a switching ratio of up to 106 and a sub-threshold swing of 87-100 mV dec-1 (left in Figure 4) .At the same time, thanks to its well-defined molecular structure, Complex of dendrimer and semiconducting single-walled carbon nanotubes with better batch repeatability and ink storage stability (right in Figure 4). Studies have shown that dendritic knots with well-defined structures Is an ideal material for the separation of single-walled carbon nanotubes. Since these compounds have a well-defined chemical structure, they can be precisely controlled and functionalized at different positions by chemical tailoring to make them into research Material Structure - Excellent model compound for performance.
The research results were published online in Advanced Functional Materials and applied for 3 invention patents and 1 PCT patent, which won the honorary titles of National Natural Science Foundation of China, Frontier Research Project of Chinese Academy of Sciences, Strategic Pilot Project of Chinese Academy of Sciences and Suzhou Nano's own Project support.
