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Lioubtchenko, Dmitri, DrORCID iD iconorcid.org/0000-0003-1443-403X
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Publications (10 of 42) Show all publications
Xenidis, N., Przewłoka, A., Stelmaszczyk, K., Haras, M., Smirnov, S., Krajewska, A., . . . Lioubtchenko, D. (2024). Dichroic absorption of aligned graphene-augmented inorganic nanofibers in the terahertz regime. Applied Materials Today, 39, Article ID 102245.
Open this publication in new window or tab >>Dichroic absorption of aligned graphene-augmented inorganic nanofibers in the terahertz regime
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2024 (English)In: Applied Materials Today, E-ISSN 2352-9407, Vol. 39, article id 102245Article in journal (Refereed) Published
Abstract [en]

This article investigates the dichroic properties of aligned γ-Al2O3 nanofibers coated with graphene in the terahertz (THz) regime, revealing significant variance in absorption based on the orientation of the electric field in relation to the nanofibers, arising from the anisotropic nature of the material. Samples are prepared in a hot-wall chemical vapor deposition reactor with varying growth times, resulting in 5 samples with increasing graphene content. Compositional characterization is carried out using scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The samples are characterized electromagnetically using two distinct measurement techniques. First, a novel waveguide measurement setup is deployed, wherein square waveguide cassettes are used to capture the anisotropic behavior of the material and equally measure both polarization states in 67–500 GHz. Then, the samples are characterized using terahertz time-domain spectroscopy up to 4 THz. Both techniques highlight absorption enhancement when the electric field is parallel to the fibers, opening new possibilities for THz devices using polarization filtering.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Anisotropy, Dichroism, Graphene, Nanofibers, Polarization, THz
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-347283 (URN)10.1016/j.apmt.2024.102245 (DOI)001248430100001 ()2-s2.0-85194361887 (Scopus ID)
Note

QC 20240613

Available from: 2024-06-10 Created: 2024-06-10 Last updated: 2024-07-05Bibliographically approved
Dróżdż, P. A., Haras, M., Przewłoka, A., Krajewska, A., Filipiak, M., Słowikowski, M., . . . Lioubtchenko, D. (2023). A graphene/h-BN MEMS varactor for sub-THz and THz applications. Nanoscale, 15(30), 12530-12539
Open this publication in new window or tab >>A graphene/h-BN MEMS varactor for sub-THz and THz applications
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2023 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 15, no 30, p. 12530-12539Article in journal (Refereed) Published
Abstract [en]

Recent development of terahertz systems has created the need for new elements operating in this frequency band, i.e., fast tunable devices such as varactors. Here, we present the process flow and characterization of a novel electronic variable capacitor device that is made with the use of 2D metamaterials such as graphene (GR) or hexagonal boron nitride (h-BN). Comb-like structures are etched into a silicon/silicon nitride substrate and a metal electrode is deposited at the bottom. Next, a PMMA/GR/h-BN layer is placed on top of the sample. As voltage is applied between GR and metal, the PMMA/GR/h-BN layer bends towards the bottom electrode thus decreasing the distance between electrodes and changing the capacitance. The high tunability and complementary metal oxide semiconductor (CMOS)-compatible process flow of the platform for our device and its millimeter size make it promising for applications in future electronics and terahertz technologies. The goal of our research is to integrate our device with dielectric rod waveguides, thus making THz phase shifters.

Place, publisher, year, edition, pages
Royal Society of Chemistry (RSC), 2023
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-334383 (URN)10.1039/d2nr06863j (DOI)001019032900001 ()37387628 (PubMedID)2-s2.0-85164362945 (Scopus ID)
Funder
EU, Horizon 2020, 862788
Note

Correction in: Nanoscale, vol. 15, issue 31, pages 13133. DOI:10.1039/D3NR90137H, Scopus:2-s2.0-85167842690

QC 20230818

Available from: 2023-08-18 Created: 2023-08-18 Last updated: 2023-08-31Bibliographically approved
Przewloka, A., Rehman, A., Smirnov, S., Karpierz-Marczewska, E., Krajewska, A., Liszewska, M., . . . Lioubtchenko, D. (2023). Conductivity inversion of methyl viologen-modified random networks of single-walled carbon nanotubes. Carbon, 202, 214-220
Open this publication in new window or tab >>Conductivity inversion of methyl viologen-modified random networks of single-walled carbon nanotubes
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2023 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 202, p. 214-220Article in journal (Refereed) Published
Abstract [en]

One of the challenges of using carbon nanotubes electronics is achieving precise control of the conductivity type. It is particularly difficult to obtain the n-type conductive nanotubes. One of the most common methods of CNTs modification allowing to change their conductivity type is chemical functionalization. This paper describes the results of studies on non-covalent modification of randomly oriented single-walled carbon nan-otubes (SWCNT) layers with methyl viologen (MV), which allows for the change of the conductivity of SWCNT from p- to n-type. The properties of pristine and MV-modified SWCNT have been compared using Scanning Electron Microscopy, Raman spectroscopy, and X-ray Photoelectron Spectroscopy. The SWCNT conductivity type change was confirmed by photo-conductance under ultraviolet illumination and measurements in the field effect transistor configuration.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Single-walled carbon nanotubes, SWCNT, Methyl viologen, Modification, UV light, Conductivity
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-322864 (URN)10.1016/j.carbon.2022.10.071 (DOI)000892293800004 ()2-s2.0-85142818676 (Scopus ID)
Note

QC 20230109

Available from: 2023-01-09 Created: 2023-01-09 Last updated: 2023-01-25Bibliographically approved
Rivera-Lavado, A., Ali, M., Gallego-Cabo, D., Garcia-Munoz, L.-E., Lioubtchenko, D. & Carpintero, G. (2023). Contactless RF Probe Interconnect Technology Enabling Broadband Testing to the Terahertz Range. IEEE Transactions on Terahertz Science and Technology, 13(1), 34-43
Open this publication in new window or tab >>Contactless RF Probe Interconnect Technology Enabling Broadband Testing to the Terahertz Range
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2023 (English)In: IEEE Transactions on Terahertz Science and Technology, ISSN 2156-342X, E-ISSN 2156-3446, Vol. 13, no 1, p. 34-43Article in journal (Refereed) Published
Abstract [en]

Radiofrequency (RF) probes based on 50-omega planar transmission lines play a key role in almost every stage of RF device development, establishing the physical contact between high-end instrumentation and the device. With the continuous downscaling of semiconductor technologies to reach into the millimeter-wave (30-300 GHz) and Terahertz (300 GHz to 3 THz) bands and devices exhibiting broader frequency response, current RF probe technology is the Achilles heel for precise and repeatable measurements. Here, we propose a novel RF probe technology based on the near-field coupling of single-mode dielectric waveguide structures, which according to our full-wave simulations provide an extremely broad frequency range covering from 0 Hz up to 340 GHz, the largest continuous bandwidth reported to date. A concept demonstrator using this approach shows contactless RF probing on test structures, which shows the path toward continuous measurements across the microwave, millimeter-wave, and Terahertz range.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
Keywords
Probes, Radio frequency, Dielectrics, Dielectric measurement, Connectors, Optical waveguides, Rectangular waveguides, Contactless probe, dielectric rod waveguide (DRW), terahertz, ultra-wideband interconnection
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Telecommunications
Identifiers
urn:nbn:se:kth:diva-324484 (URN)10.1109/TTHZ.2022.3213470 (DOI)000920767700006 ()2-s2.0-85139876835 (Scopus ID)
Note

QC 20230314

Available from: 2023-03-14 Created: 2023-03-14 Last updated: 2023-03-14Bibliographically approved
Drozdowska, K., Rehman, A., Smulko, J., Krajewska, A., Stonio, B., Sai, P., . . . Rumyantsev, S. (2023). Optimum Choice of Randomly Oriented Carbon Nanotube Networks for UV-Assisted Gas Sensing Applications. ACS Sensors, 8(9), 3547-3554
Open this publication in new window or tab >>Optimum Choice of Randomly Oriented Carbon Nanotube Networks for UV-Assisted Gas Sensing Applications
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2023 (English)In: ACS Sensors, E-ISSN 2379-3694, Vol. 8, no 9, p. 3547-3554Article in journal (Refereed) Published
Abstract [en]

We investigated the noise and photoresponse characteristics of various optical transparencies of nanotube networks to identify an optimal randomly oriented network of carbon nanotube (CNT)-based devices for UV-assisted gas sensing applications. Our investigation reveals that all of the studied devices demonstrate negative photoconductivity upon exposure to UV light. Our studies confirm the effect of UV irradiation on the electrical properties of CNT networks and the increased photoresponse with decreasing UV light wavelength. We also extend our analysis to explore the low-frequency noise properties of different nanotube network transparencies. Our findings indicate that devices with higher nanotube network transparencies exhibit lower noise levels. We conduct additional measurements of noise and resistance in an ethanol and acetone gas environment, demonstrating the high sensitivity of higher-transparent (lower-density) nanotube networks. Overall, our results indicate that lower-density nanotube networks hold significant promise as a viable choice for UV-assisted gas sensing applications.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
Keywords
biocontrol, carbon nanotubes, ethanol, gas sensor, low-frequency noise, UV irradiation
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-337410 (URN)10.1021/acssensors.3c01185 (DOI)001065437200001 ()37682632 (PubMedID)2-s2.0-85172034179 (Scopus ID)
Note

QC 20231003

Available from: 2023-10-03 Created: 2023-10-03 Last updated: 2024-03-05Bibliographically approved
Bryantseva, T. A., Lyubchenko, V. E., Lyubchenko, D., Markov, I. A. & Ten, Y. A. A. (2023). Peculiarities of the Formation and Growth of Thin Gold Films on the Surface of Gallium Arsenide during Thermal Evaporation in Vacuum. Journal of communications technology & electronics, 68(5), 566-574
Open this publication in new window or tab >>Peculiarities of the Formation and Growth of Thin Gold Films on the Surface of Gallium Arsenide during Thermal Evaporation in Vacuum
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2023 (English)In: Journal of communications technology & electronics, ISSN 1064-2269, E-ISSN 1555-6557, Vol. 68, no 5, p. 566-574Article in journal (Refereed) Published
Abstract [en]

Changes in the morphology and structure of the GaAs surface during the deposition of an Au film by thermal evaporation in vacuum have been studied. It has been found that the deposition of an Au film with the participation of a flow of particles and light from a heated evaporator causes the appearance of photo effects in the near-surface GaAs layers, including light diffraction on surface acoustic waves, the growth of whiskers, and electron emission, which leads to the formation of microcracks on the GaAs surface and the growth of GaAs crystallites. It is shown that the structure and composition of the film boundaries of Au and GaAs surfaces depend on the electron concentration in gallium arsenide, which ultimately determines the properties of the electrophysical parameters of the Au-GaAs contacts.

Place, publisher, year, edition, pages
Pleiades Publishing Ltd, 2023
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-333794 (URN)10.1134/S1064226923050030 (DOI)001022443400011 ()2-s2.0-85163633436 (Scopus ID)
Note

QC 20230810

Available from: 2023-08-10 Created: 2023-08-10 Last updated: 2023-08-10Bibliographically approved
Xenidis, N., Smirnov, S., Przewloka, A., Krajewska, A., Oberhammer, J. & Lioubtchenko, D. (2023). Waveguide Measurements of Highly Anisotropic Graphene Augmented Inorganic Nanofibers. In: 2023 53rd European Microwave Conference, EuMC 2023: . Paper presented at 53rd European Microwave Conference, EuMC 2023, Berlin, Germany, Sep 19 2023 - Sep 21 2023 (pp. 576-579). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Waveguide Measurements of Highly Anisotropic Graphene Augmented Inorganic Nanofibers
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2023 (English)In: 2023 53rd European Microwave Conference, EuMC 2023, Institute of Electrical and Electronics Engineers (IEEE) , 2023, p. 576-579Conference paper, Published paper (Refereed)
Abstract [en]

This work presents the preparation and the frequency domain measurements of graphene augmented inorganic nanofibers oriented across the longitudinal axis of the fibers, embedded in a hollow WR-10 waveguide cassette. A simple measurement setup is employed, allowing for rapid, broadband characterization of the material under test. Due to the orientation of the fibers, highly anisotropic behavior is revealed.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
Keywords
anisotropy., carbon, graphene, sub-THz, W-band, Waveguide
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-340374 (URN)10.23919/EuMC58039.2023.10290484 (DOI)001101795000144 ()2-s2.0-85177589092 (Scopus ID)
Conference
53rd European Microwave Conference, EuMC 2023, Berlin, Germany, Sep 19 2023 - Sep 21 2023
Note

Part of ISBN 9782874870729

QC 20231204

Available from: 2023-12-04 Created: 2023-12-04 Last updated: 2024-03-18Bibliographically approved
Kumar, A., Gallego, D. C., Headland, D., Ali, M., Xenidis, N., Lioubtchenko, D. & Carpintero, G. (2022). Contactless Cost-effective Polarizer for mm-Wave Dielectric Rod Waveguide. In: 2022 47TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ 2022): . Paper presented at 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz), AUG 28-SEP 02, 2022, Delft, NETHERLANDS. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Contactless Cost-effective Polarizer for mm-Wave Dielectric Rod Waveguide
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2022 (English)In: 2022 47TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ 2022), Institute of Electrical and Electronics Engineers (IEEE) , 2022Conference paper, Published paper (Refereed)
Abstract [en]

We present a method to control the polarization of guided waves in a mm-wave dielectric rod waveguide. A pair of optical posts is situated on either side of the waveguide, and this markedly raises the cutoff of the undesired mode. The isolation is 20 dB over a frequency span from (55-87) GHz. This can be viewed as a proof-of-concept for reconfigurable, general-purpose polarization control and dispersion engineering in mm-wave and terahertz-range dielectric waveguides.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2022
Series
International Conference on Infrared Millimeter and Terahertz Waves, ISSN 2162-2027
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-322180 (URN)10.1109/IRMMW-THz50927.2022.9895990 (DOI)000865953000472 ()2-s2.0-85139826522 (Scopus ID)
Conference
47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz), AUG 28-SEP 02, 2022, Delft, NETHERLANDS
Note

QC 20221205

Available from: 2022-12-05 Created: 2022-12-05 Last updated: 2022-12-05Bibliographically approved
Smirnov, S., Xenidis, N., Oberhammer, J. & Lioubtchenko, D. (2022). Generation of High-order Modes in Sub-THz Dielectric Waveguides by Misalignment of the Transition Structure. In: 2022 IEEE/MTT-S International Microwave Symposium - IMS 2022: . Paper presented at 2022 IEEE/MTT-S International Microwave Symposium, IMS 2022, Denver, 19 June 2022, through 24 June 2022 (pp. 479-482). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Generation of High-order Modes in Sub-THz Dielectric Waveguides by Misalignment of the Transition Structure
2022 (English)In: 2022 IEEE/MTT-S International Microwave Symposium - IMS 2022, Institute of Electrical and Electronics Engineers (IEEE), 2022, p. 479-482Conference paper, Published paper (Refereed)
Abstract [en]

Dielectric waveguides are a potential platform for future integrated THz electronics but are still challenging to interface with standard measurement equipment. The commonly used tapered transition to hollow metallic waveguides involves manual alignment, leading to measurement inaccuracies. In this paper, we report the effects of misalignment between a dielectric and a metallic waveguide in the W-band. The results indicate the excitation of unwanted high-order modes in the dielectric waveguide that are expected to degrade the performance, especially at higher frequencies.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2022
Series
IEEE MTT-S International Microwave Symposium, ISSN 0149-645X ; 2022-June
Keywords
Dielectric waveguides, high order modes, millimeter wave devices, transition structures
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:kth:diva-320426 (URN)10.1109/IMS37962.2022.9865497 (DOI)000862782300122 ()2-s2.0-85137982994 (Scopus ID)
Conference
2022 IEEE/MTT-S International Microwave Symposium, IMS 2022, Denver, 19 June 2022, through 24 June 2022
Note

QC 20221021

Part of proceedings: ISBN 978-1-6654-9613-1

Available from: 2022-10-21 Created: 2022-10-21 Last updated: 2022-10-21Bibliographically approved
Drozdz, P. A., Xenidis, N., Campion, J., Smirnov, S., Przewloka, A., Krajewska, A., . . . Lioubtchenko, D. (2022). Highly efficient absorption of THz radiation using waveguide-integrated carbon nanotube/cellulose aerogels. APPLIED MATERIALS TODAY, 29, Article ID 101684.
Open this publication in new window or tab >>Highly efficient absorption of THz radiation using waveguide-integrated carbon nanotube/cellulose aerogels
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2022 (English)In: APPLIED MATERIALS TODAY, ISSN 2352-9407, Vol. 29, article id 101684Article in journal (Refereed) Published
Abstract [en]

This article presents the preparation, compositional and electromagnetic characterization of modified few-walled carbon nanotubes/nanofibrillar cellulose (FWCNT/NFC) aerogels integrated in a standard terahertz hollow waveguide and studies their operation as absorbers of electromagnetic waves in the WR-3.4 band (220-330 GHz). Hybrid aerogels consisting of different weight ratios of NFC and modified FWCNT are prepared by freezedrying and characterized through scanning electron microscopy and Raman spectroscopy, and then placed within waveguide cassettes in a simple, low-cost and efficient way that requires no special equipment. A broadband measurement setup is employed for examining the electromagnetic response of the materials. It is found that the materials are excellent absorbers with an average shielding efficiency of 66 dB in the best case and return loss above 10 dB across the band with a flat frequency response. FWCNT aerogels are assessed as a promising candidate for terahertz waveguide terminations.

Place, publisher, year, edition, pages
Elsevier BV, 2022
Keywords
Carbon nanotubes, Nanofibrillar cellulose, Aerogels, Absorber, Sub-THz, Waveguide integrated absorbers
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-322865 (URN)10.1016/j.apmt.2022.101684 (DOI)000891769900004 ()2-s2.0-85141791885 (Scopus ID)
Note

QC 20230109

Available from: 2023-01-09 Created: 2023-01-09 Last updated: 2023-01-09Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-1443-403X

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