Kitabı oku: «First virtual Bilateral Conference on Functional Materials (BiC-FM)», sayfa 11

Ultrashort optical Mathieu pulses in a carbon nanotube medium

Dvuzhilova Yu.V.¹, Belonenko A.M.¹, Dvuzhilov I.S.¹, Belonenko M.B.¹

1 – Volgograd State University, Volgograd, Russia

dvuzhilov.ilya@volsu.ru

A theoretical study of three-dimensional ultrashort optical pulses, Mathieu cross-section, which propagate in the medium of semiconductor carbon nanotubes. Using numerical simulations, it is shown that such pulses propagate stably, while conserving their energy in a limited spatial region. The pulse undergoes reflection from the walls of the optical cavity and further interference. The calculations were carried out at times up to 140 ps, which is important for possible practical applications [1–4].

Thus, diffraction-free three-dimensional extremely short Mathieu pulses propagate stably in the medium of carbon nanotubes. The pulse energy remains localized in a limited spatial region. Evolving in time, the pulse moves from the axis of the resonator to its walls, reflecting from them, and then interference of counter propagating waves occurs, due to which the pulse retains its energy concentrated, with a slight change in shape.

As a result, it becomes possible to control pulse broadening along the cavity axis. It should be noted that the numerical simulation of the pulse dynamics was carried out at long times, which determines the importance of the results obtained for practical applications.

Acknowledgement.The reported research was funded by Russian Foundation for Basic Research and the government of Volgograd region, grant № 19-43-340005 r_a.

References:

[1] M.A. Bandres, J.C. Gutiérrez-Vega, S. Chávez-Cerda, Optics Letters, 29, P. 44 (2004)

[2] J.W. Jiang, J.S. Wang, Journal of Applied Physics, 110, P. 124319 (2011)

[3] H. Leblond, D. Mihalache, Physical Review A, 86, P. 043832 (2012)

[4] Zhukov A.V., Bouffanais R., Belonenko M.B., Dvuzhilov I.S., Nevzorova, Y.V., Applied Physics B, 123 (2017)

The technology for producing new composite polymer materials based on polymethylmethacrylate doped with carbon nanotubes

Elbakyan L.S.¹, Zaporotskova I.V.¹, Vilkeeva D.E.¹

1 – Institute of Priority technologies, Volgograd State University, University Av 100, Volgograd 400062, Russia

lusniak-e@yandex.ru

Butylmethacrylate is used for the production of polybutylmethacrylates and related copolymers. BMA is used in the production of coatings and inks, plastics, paper, adhesives and sealants. In addition, BMA is a part of adhesives, photo-cured and other composites for dental use, various additives to lubricants, etc.[1]

To realize the possibility of obtaining composite polymer materials with improved strength properties, it is necessary to ensure the most uniform dispersion of carbon nanotubes into the polymer matrix. To create and test the technology of introducing CNT into polymer matrices, the method of ultrasonic action with simultaneous mechanical mixing under temperature influence was developed [2–4]. This method makes it possible to obtain stable polymer complexes, to increase the strength characteristics of the polymer. To study the strength properties of the obtained polymer materials, the breaking point of these samples with different percentages of CNT and the sample without them was determined.

Table 2. The breaking point composite polymer materials doped with CNT

CNT, % – Breaking point σ_ср, [MPa]

0 – 0,041

0,01 – 0,043

0,03 – 0,046

0,05 – 0,049

Experimental studies on the creation of stable polymer complexes make it possible to obtain new composite systems reinforced with carbon nanotubes. This makes it possible to predict a larger-scale use of polymer materials.

Acknowledgement.The research was carried out with the financial support of the RFBR and the administration of the Volgograd region in the framework of the scientific project no.19-43-340005 r_a.

References:

[1] George Wypych Handbook of Polymers, Second Edition. ChemTec Publishing (2016) 712.

[2] L.S. Elbakyan, I.V. Zaporotskova Obtaining New Dental Materials Reinforced with Carbon Nanotubes, J. of nano- and electronic physics. Vol. 6, № 3 (2014) 03008-1 – 03008-3.

[3] M.S. Dresselhaus, G. Dresselhaus, P. Avouris, Carbon Nanotubes: Synthesis, Structure, Properties, and Application, Berlin/Heidelberg, Germany, 2001.

[4] L. S. Elbakyan, I. V. Zaporotskova. On the possibility of creating polymer nanocomposites based on methacrylic acid by reinforcing them with carbon nanotubes, J. Eurasian Union of scientists. Kh. (2014) 39–42.

Synthesis of Pt nano-microspheres at TiO₂ – decorated Ti wire

Fedorov F.S.¹, Vasilkov M.Yu.^2,3, A. Goldt¹, Shurygina L.I.⁴, Nasibulin A.G.^1,5

1 – Skolkovo Institute of Science and Technology, Moscow, Russia

2 – Saratov Branch of Kotelnikov Institute of Radioengineering and Electronics of RAS, Saratov, Russia

3 – Yuri Gagarin State Technical University of Saratov, Saratov, Russia

4 – Kemerovo State University, Kemerovo, Russia.

5 – Aalto University, Aalto, Finland

f.fedorov@skoltech.ru

Nowadays the development of new functional materials with improved characteristics for application in electrocatalysis [1], gas sensors, etc. [2] is directly related to their design at the nanoscale. However, one needs to consider appearing technological issues, i.e. the applicability of such nanostructured materials in the industry. For example, the use of arrays of titanium dioxide nanotubes at the Ti substrate may include potential applications when it is in the form of wires or meshes that enable flow-through design. But, anodization of the metal of such geometries is not trivial because the surface profile is characterized by a given curvature. Besides, modifying the surface of such structures with precious metals such as platinum, which helps to improve the catalytic activity, can be quite challenging. Here, we investigated the growth processes of titanium dioxide nanotube arrays obtained by anodizing titanium wire in aqueous organic solutions and the decoration of such arrays with platinum.

Electrochemical anodization of a titanium wire (d=250 µm, ω(Ti)=99.7 %-wt.) was studied in an electrolyte containing glycerol, water, and ammonium fluoride with a mass ratio of 74.6: 24.6: 0.75 at a constant voltage of 30 V for 70 hours. Further, the obtained samples were modified with platinum in a solution of 400 µl 0.02 M H₂PtCl₆, 400 µl H₂O, and 400 µl 85 %-wt. HCOH for 120 hours. The obtained samples were studied by scanning electron microscopy with a help of a focused ion beam and transmission electron microscopy.

The synthesized structures represent arrays of ordered nanotubes decorated with platinum. The platinum appears as polycrystalline spheres whose diameter ranges from 100 nm to 2–3 µm. The structure of the spheres is represented as a complex network of nanowires with voids made by titanium dioxide nanotubes. This material has a large surface area and is promising for application as a gas sensor and as a catalyst.

Acknowledgment.This work was supported by a grant of Russian Science Foundation (no. 19-72-00136).

References:

[1] F.S. Fedorov et al. International Journal of Hydrogen Energy, 44, 10593 (2019)

[2] A.V Lashkov et al. Sensors & Actuators B: Chemical, 306, 127615 (2020)

New phosphates and fluoride-phosphates as promising electrode materials for rechargeable batteries

Luchinin N. D.¹, Samarin A. Sh.¹, Shraer S. D.¹, Fedotov S. S.¹

1 – Skolkovo Institute of Science and Technology, Moscow, Russia

s.fedotov@skoltech.ru

The progress in grid applications of metal-ion batteries pushes forward the development of electrode materials for Na-ion and K-ion batteries (NIBs and KIBs) as cost-efficient alternatives to the conventional Li-ion technology. Analogous to the Li-ion systems, the Na and K-based mixed oxides and polyanion materials are being developed as potential cathodes with attractive specific energy, stability and rate performance. Contrary to layered oxides, the polyanion materials usually display better cycling and thermal stability, as well as higher C-rate capabilities due to covalently bonded structural frameworks. At the same time, the polyanion compounds reveal a much more diverse crystal chemistry, which significantly extends the playground for designing new materials with unique electrochemical properties. Further advancements come from the synergy of coupling different anion species (such as XO₄^m- and F^-) in the anion sublattice enabling higher redox potentials and richer structural diversity.

Recently we proposed a novel series of AMPO₄F (A = Li, Na, K; M = Ti, V) cathode materials crystallizing in a unique KTiOPO₄ (KTP)-type structure [1–4]. The target materials were synthesized via different soft-chemistry routes including hydrothermal method and freeze-drying. The materials featured outstanding specific energy, rate capability, and capacity retention outperforming most of benchmarked NIBs and KIBs electrode materials.

A short overview of the recent research and activities of our group on novel transition metal phosphates and fluoride-phosphates adopting the unique KTP-type crystal structure as potential electrode materials for NIBs and KIBs will be presented with a special focus on the interrelation between chemical composition, synthesis conditions, crystal structure peculiarities, and electrochemical properties of the materials aimed at practical applications.

Acknowledgement.This work was supported by the Russian Science Foundation, grant 20-73-10248.

References:

[1] S.S. Fedotov et al Chemistry of Materials, 28, 411 (2016)

[2] S.S. Fedotov et al Nature Communications, 11, 1 (2020)

[3] S.S. Fedotov et al Journal of Power Sources 480, 228840 (2020)

[4] S.S. Fedotov et al Journal of Materials Chemistry A, 6, 14420 (2018)

Dip-coating as efficient technique for single-walled carbon nanotube doping

Anastasia E. Goldt¹, Orysia T. Zaremba¹, Eldar M. Khabushev^1,2, Stepan A. Romanov¹,

Albert G. Nasibulin^1,2

¹Skolkovo Institute of Science and Technology, 3 Nobel Street, Moscow, 121205, Russia

²Aalto University School of Chemical Engineering, Kemistintie 1, 02015, Espoo, Finland

a.goldt@skoltech.ru

Single-walled carbon nanotube (SWCNT) based transparent and conductive films (TCFs) are one of the most prospective materials for novel flexible and stretchable electronic devices. Development of reproducible and scalable doping procedure is the key step towards the widespread implementation of SWCNT TCFs.

We propose and thoroughly investigate a novel approach for SWCNTs doping utilizing traditional dip-coating technique with gold (III) chloride solution as a dopant. Adjusting of the process conditions (dopant concentration and withdrawal speed) allows effectively govern SWCNT film doping degree and define the optimal conditions for fabrication of high-performance nanotube films. It leads to achievement of sheet resistance value of 36 Ohm/sq. at the 90 % transmittance the middle of visible spectral range by increasing a work function value from 4.8 (for pristine SWCNTs) to 6.0 eV.

This method allows easy fine-tuning of SWCNT films optoelectronic parameters and achieve a sheet resistance value of 36 Ohm/sq. at the 90 % transmittance in the middle of visible spectral range by increasing a work function value from 4.8 (for pristine SWCNTs) to 6.0 eV

In addition, the fabrication of uniform, highly conductive and transparent SWCNT films opens a space for the development of a robust continuous roll-to-roll process by immersing roller modules into a dopant solution.

Acknowledgement.The authors acknowledge the Russian Science Foundation (project No. 17-19-01787).

Dielectric properties of intercalated graphite fluoride compounds with bromine and acetonitrile

Grebenkina M.A.^1,2, Chekhova G.N.¹, Pinakov D.V.¹, Gusel'nikov A.V.¹, Bulusheva L.G.^1,2, Okotrub A.V.^1,2

1 – Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, Russia

2 – Novosibirsk State University, Novosibirsk, Russia

grmariya@mail.ru

Fluorinated graphite intercalated compounds (FGICs) consist of a layered matrix formed by graphene layers with attached fluorine atoms and guest molecules, which are embedded in the interlayer space [1]. The study of the dielectric properties of FGICs will provide information of the intercalated molecules’ arrangement in the interlayer space and the effect of intercalated molecules and the matrix’s composition on the dielectric permittivity of the material.

In this research we investigated the temperature and the frequency dependences of the dielectric permittivity of FGICs with matrixes’ compositions C₂F_1,05, C₂F_0,85, C₂F_0,60 and inserted bromine (Br₂) or acetonitrile (CH₃CN). The temperature was varied from 180 to 25 °C, the frequency – from 1 Hz to 7 MHz. It was indicated that low-fluorinated graphite intercalated with bromine has extremely high dielectric permittivity. The effect is associated with the formation of Br₂^- and Br₃^- ions which lead to an increase in the dielectric response and the appearance of an ion-relaxation mechanism of polarization. In highly fluorinated samples, interaction between Br₂ molecules are similar to that of a liquid. Moreover, it was demonstrated that the freezing of the movement of acetonitrile CH₃CN molecules in the interplanar space of graphite fluorides occurs at temperatures below -100 °C what causes a decrease of the dielectric permittivity of FGIGs.

Acknowledgement.This work was supported by the Russian Foundation for Basic Research, grant 18-29-19073.

References:

[1] G.N. Chekhova, D.V. Pinakov, Yu.V. Shubin, V.P. Fadeeva, V.D. Tikhova, A.V. Okotrub, L.G. BulushevaJ. Fluor. Chem. Elsevier B.V., 232, 109482 (2020).

Fine tuning of single-walled carbon nanotube properties for transparent and conductive applications

Khabushev E.M.^1,2, Krasnikov D.V.¹, Tsapenko A.P.^1,2, Zaremba O.T.¹, Kolodyaznaya Y.V.¹, Goldt A.E.¹, and Nasibulin A.G.^1,2

1 – Skolkovo Institute of Science and Technology, Moscow, Russia

2 – Aalto University, Espoo, Finland

eldar.khabushev@skoltech.ru

Single-walled carbon nanotubes (SWCNTs) are still a material attracting a significant attention of the scientific community: current technological advances are focused on their implementation in novel optoelectronic devices [1]. Currently, aerosol CVD is a well-established technique to produce SWCNTs of high quality, possessing excellent scalability and material purity. Nevertheless, precise control over output parameters is still not achieved that hampers SWNCT widespread implementation.

In this work SWCNT synthesis by aerosol CVD based on the Boudouard reaction utilizing ferrocene as catalyst precursor. We inspected the influence of synthesis conditions (temperature, carbon dioxide and ferrocene partial pressure) on SWCNT parameters utilizing the four-probe technique, Raman and optical spectroscopy and electron microscopy. Finely tuning synthesis parameters, we obtained SWCNTs with a mean diameter varying in the range from 1 to 2 nm and Raman quality factor I_G/I_D up to 500. Analyzing the obtained results, we prove a high Raman peak ratio (I_G/I_D), length, and diameter of the nanotubes to decrease the equivalent sheet resistance of the nanotube-based film [2]. Temperature kinetic measurements revealed the change in the nanotube growth mechanism at the temperature coinciding with the phase transition between α-Fe and γ-Fe catalyst phases, which highlighted a significant difference in the conductive properties of films producing at different synthesis temperatures.

As a result of equivalent sheet resistance optimization, we obtained pristine films with R₉₀=250 Ω/. Moreover, this value dropped down to 39 Ω/ after HAuCl₄ doping providing

Acknowledgement.This work was supported by Russian Foundation for Basis Research grant 18-29-20032

References:

[1] J. Du, S. Pei, L. Ma, H.M. Cheng, Advanced Materials, 26, 1958–1991, (2014).

[2] E.M. Khabushev, D. V. Krasnikov, J. V. Kolodiazhnaia, A. V. Bubis, A.G. Nasibulin, Carbon, 161, 712–717, (2020).

[3] E.M. Khabushev, D. V. Krasnikov, O.T. Zaremba, A.P. Tsapenko, A.E. Goldt, A.G. Nasibulin, Journal of Physical Chemistry Letters 10, 6962–6966, (2019).

Holey single-walled carbon nanotubes for ultra-fast bolometers

Daria S. Kopylova¹*, Fedor S. Fedorov¹, Alena А. Alekseeva¹, Zakhar I. Popov², Pavel B. Sorokin², Anton S. Anisimov³, and Albert G. Nasibulin^1,4

¹Skolkovo Institute of Science and Technology, Nobel str. 3, Moscow, 121205, Russia

²National University of Science and Technology MISIS, Leninskiy prospect, 4, Moscow, 119049, Russia

³Canatu Ltd. Konalankuja 5, 00390, Helsinki, Finland

⁴Aalto University, Department of Applied Physics, 00076, Aalto, Finland

D.Kopylova@skoltech.ru

The development of new materials for sensitive and fast broadband photodetectors remains actual problem in the fields of IR vision and spectroscopy. Carbon nanotubes have already been demonstrated as a promising material for bolometers [1]. However, the sensitivity enhancement of such bolometers while maintaining the speed of operation is still a great challenge. Here, we present a new material, holey carbon nanotube network, designed to improve the temperature coefficient of resistance (TCR), the key parameter that determine the sensitivity of bolometers [2]. Fine treatment with low frequency oxygen plasma allows to control the conductive properties of the material. The temperature coefficient of resistance of our films is much higher than reported values for pristine carbon nanotubes in wide temperature range up to 3 % K^-1 in absolute value at liquid nitrogen temperature which is much higher than reported values for carbon nanotubes and comparable with vanadium oxides. The bolometer prototypes made of free-standing plasma treated SWCNT films possess high sensitivity in wide IR range (3-50 µm), smooth spectral characteristics of IR absorption, ultrafast (3 ms) response time and relatively low noise level comparing to similar devices made of carbon nanotubes.

Acknowledgement. The reported study was funded by RFBR, project number 20-03-00804.

Fig.1 The plasma treatment effect on TCR of SWCNT films and bolometers response (a) TCR of pristine SWCNT films and the ones treated in oxygen plasma at different exposure time, inset: temperature dependence of film sheet resistance. (b) Spectral characteristics of bolometric samples made of 100 nm thick free-standing SWCNT film, pristine and oxygen plasma treated with different time of treatment.

A simple and reliable approach to fabricate arrays of single-walled carbon nanotube network field-effect transistor for advanced characterization

Grigoriy B. Livshits¹, Alena A. Alekseeva¹, Anton V. Bubis¹, Dmitry V. Krasnikov¹, Albert G. Nasibulin^1,2

¹Skolkovo University of Science and Technology, Moscow, Russia

²Aalto University School of Chemical Engineering, Espoo, Finland

Grigoriy.Livshits@skoltech.ru

Nowadays, flexible electronics demands new materials for integrated circuits of high flexibility and stretchability^[1]. Single-walled carbon nanotubes (SWCNTs) are one of the most promising materials for utilization in the flexible integrated circuits owing to the outstanding electrical and mechanical properties^[2]. Field-effect transistors (FETs) with on/off ratio of 10⁸ and 100 cm²/(V∙s) have already been reported on SWCNT films purified from metallic nanotubes^[3] as well as on pristine films^[4]. However, implementation of developed technologies in industry seeks advances in both the fabrication technology and deeper understanding of interplay between SWCNT film properties.

Here we present a technology for SWCNT film-based FETs that can be used as a versatile tool for examination of intrinsic properties of the films. The method relies on a simple capillary transfer technique of as-synthesized SWCNT film from a nitrocellulose filter. The method is simple, scalable, and does not require tedious and contaminating procedure of filter dissolution. We have fabricated a series of SWCNT FET arrays to demonstrate the advanced quality and uniformity of the transfer. The relation of FET parameters (such as opened and closed state resistance, on/off ratio etc.) can be easily brought to light via the procedure proposed. We have investigated the relations in the vast range of on/off ratio (10–10⁶) and on-state resistance (10⁴ – 10⁸ Ω) on SWCNT film FETs with channel lengths in range of 60-350 μm. Moreover, this framework can provide access for more fundamental quantities such as SWCNT film density^[5], metallic to semiconducting nanotube ratio, doping level etc^[6].

Acknowledgement.The authors acknowledge the Russian Science Foundation (project No. 17-19-01787).

References:

[1] Q. Huang and Y. Zhu, “Printing Conductive Nanomaterials for Flexible and Stretchable Electronics: A Review of Materials, Processes, and Applications,” Adv. Mater. Technol., vol. 4, no. 5, pp. 1-41, 2019, doi: 10.1002/admt.201800546.

[2] D. Jariwala, V. K. Sangwan, L. J. Lauhon, T. J. Marks, and M. C. Hersam, “Carbon nanomaterials for electronics, optoelectronics, photovoltaics, and sensing,” Chem. Soc. Rev., vol. 42, no. 7, pp. 2824–2860, 2013, doi: 10.1039/c2cs35335k.

[3] W. Talsma et al., “Remarkably Stable, High-Quality Semiconducting Single-Walled Carbon Nanotube Inks for Highly Reproducible Field-Effect Transistors,” Adv. Electron. Mater., vol. 5, no. 8, 2019, doi: 10.1002/aelm.201900288.

[4] D. M. Sun et al., “Flexible high-performance carbon nanotube integrated circuits,” Nat. Nanotechnol., vol. 6, no. 3, pp. 156–161, 2011, doi: 10.1038/nnano.2011.1.

[5] A. Kaskela, K. Mustonen, P. Laiho, Y. Ohno, and E. I. Kauppinen, “Toward the Limits of Uniformity of Mixed Metallicity SWCNT TFT Arrays with Spark-Synthesized and Surface-Density-Controlled Nanotube Networks,” ACS Appl. Mater. Interfaces, vol. 7, no. 51, pp. 28134-28141, 2015, doi: 10.1021/acsami.5b10439.

[6] N. Wei et al., “Fast and Ultraclean Approach for Measuring the Transport Properties of Carbon Nanotubes,” Adv. Funct. Mater., vol. 1907150, pp. 1–9, 2019, doi: 10.1002/adfm.201907150.