Читать книгу First virtual Bilateral Conference on Functional Materials (BiC-FM) - Сборник статей, Андрей Владимрович Быстров, Анна Владимировна Климович - Страница 6

Qiang Zhang, Datta Sukanta, Hua Jiang, Esko I. Kauppinen

Department of Applied Physics, Aalto University School of Science, PO Box 15100, FI-00076 Aalto, Espoo, FINLAND

esko.kauppinen@aalto.fi

Many efforts have been devoted to increasing the conductivity of CNT TCFs made with the floating catalyst chemical vapor deposition (FC–CVD). However, intrinsic nanotube collisions in the aerosol process of FC–CVD lead to a tread-off between yield and performance, because bundling increases when increasing the yield i.e. production rate, with the bundling reducing the growth rate as well as increasing sheet resistance at the given film transmittance. Here, we report TCFs of large-diameter CNTs from methane-based FC–CVD overcoming the performance-yield tradeoff. Based on the Fe-C-S system, the double-wall CNTs (DWCNTs) with a mean diameter of 4.15 nm and a mean bundle length of 20 um have been synthesized via FC–CVD and directly deposited to form TCFs. After gold chloride solution doping, the TCFs have an excellent performance of 42 ohm/sq sheet resistance at 90 % transmittance. Unexpectedly, these high-performance DWCNTs films have an ultra-high yield i.e. production rate, being two orders of magnitude higher than that of SWCNT based TCFs with similar performance. Especially, these high-yield DWCNTs films contain ‘small’ bundles with around 50 % of CNTs being individual, which is completely different from other FC–CVD results for SWCNTs produced at much lower yield. Moreover, the large-diameter DWCNTs seem to flatten at the junctions, which may provide a larger contact area between the tubes and accordingly reduce the contact resistance. These unique features of large-diameter CNTs in ‘small’ bundles offer the route to obtain high-performance CNT TCFs with high yield. These results imply a new model with optimization windows for high-performance CNT TCFs with high yields and accordingly at reduced cost, and may accelerate the practical application of CNTs TCFs.

Professor Esko I. Kauppinen, PhD (Physics) is the Vice-Dean responsible for research, innovations and industry relationships at the Aalto University School of Science and Tenured Professor of Physics at the Department of Applied Physics. He has published more than 443 scientific journal papers e.g. in Nature Nanotechnology, NanoLetters, ACS Nano, Angewandte Chemie, Carbon, Energy and Environmental Sciences etc., having Hirsch-index over 52 and over 10 600 citations. He has given more than 120 keynote and invited conference talks and 220 talks at world leading companies and universities. He is considered one of the world leading authors in the area of single walled carbon nanotube synthesis, characterisation and thin film applications as well as in the gas phase synthesis of particles for inhalation drug delivery. He is the founding member of the companies Canatu Oy (http://www.canatu.com) and Teicos Pharma Oy (www.teicospharma.com).