Hehua Jin

Solution-Processable High-Purity Semiconducting SWCNTs for Large-Area Fabrication of High-Performance Thin-Film Transistors

For the large-area fabrication of thin-film transistors (TFTs), a new conjugated polymer poly[9-(1-octylonoyl)-9H-carbazole-2,7-diyl] is developed to harvest ultrahigh-purity semiconducting single-walled carbon nanotubes. Combined with spectral and nanodevice characterization, the purity is estimated up to 99.9%. High density and uniform network formed by dip-coating process is liable to fabricate high-performance TFTs on a wafer-scale and the as-fabricated TFTs exhibit a high degree of uniformity.

A Mixed‐Extractor Strategy for Efficient Sorting of Semiconducting Single‐Walled Carbon Nanotubes

A general strategy for sorting semiconducting single-walled carbon nanotubes (s-SWNTs) with high efficiency using a mixed-extractor is reported. When the two extractors have a sufficient difference in binding energy with s-SWNTs, and skeleton flexibility, the mixture shows enhanced yield for sorting s-SWNTs. The strategy could be effective when applied to increase the sorting yield of other selective dispersion systems.

Recycling Strategy for Fabricating Low-Cost and High-Performance Carbon Nanotube TFT Devices

High-purity semiconducting single-walled carbon nanotubes (s-SWNTs) can be obtained by conjugated polymer wrapping. However, further purification of sorted s-SWNTs and high costs of raw materials are still challenges to practical applications. It is inevitable that a lot of polymers still cover the surface of s-SWNTs after separation, and the cost of the polymer is relatively higher than that of SWNTs. Here, we demonstrated a facile isolated process to improve the quality of s-SWNT solutions and films significantly. Compared with the untreated s-SWNTs, the contact resistance between the s-SWNT and the electrode is reduced by 20 times, and the thin-film transistors show 300% enhancement of current density. In this process, most of the polymers can be recycled and reused directly without any purification, which can greatly decrease the cost for s-SWNT separation. The results presented herein demonstrate a new scalable and low-cost approach for large-scale application of s-SWNTs in the electronics industry.

Low Hysteresis Carbon Nanotube Transistors Constructed via a General Dry-Laminating Encapsulation Method on Diverse Surfaces

Electrical hysteresis in carbon nanotube thin-film transistor (CNTTFT) due to surface adsorption of H2O/O2 is a severe obstacle for practical applications. The conventional encapsulation methods based on vacuum-deposited inorganic materials or wet-coated organic materials have some limitations. In this work, we develop a general and highly efficient dry-laminating encapsulation method to reduce the hysteresis of CNTTFTs, which may simultaneously realize the construction and encapsulation of CNTTFT. Furthermore, by virtue of dry procedure and wide compatibility of PMMA, this method is suitable for the construction of CNTTFT on diverse surface including both inorganic and organic dielectric materials. Significantly, the dry-encapsulated CNTTFT exhibits very low or even negligible hysteresis with good repeatability and air stability, which is greatly superior to the nonencapsulated and wet-encapsulated CNTTFT with spin-coated PMMA. The dry-laminating encapsulation strategy, a kind of technological innovation, resolves a significant problem of CNTTFT and therefore will be promising in facile transferring and packaging the CNT films for high-performance optoelectronic devices.

Chiral-separation of single-walled carbon nanotubes in the solution

Based on the solution separation strategy, we reviewed the recent progress in the approach that single-walled carbon nanotubes (SWCNTs) are dispersed or selectively dispersed by surfactants, biomolecular or conjugated polymers in solution, and then sorted out with several separation techniques to obtain single-chirality SWCNTs. We demonstrated the separation mechanism of SWCNTs by the different systems and gave a comprehensive evaluation with these techniques. Sustained progress in the separation techniques of single-chirality SWCNTs will greatly promote the further research and application of SWCNTs.