Mykhaylo Petrychuk - Academia.edu (original) (raw)

Papers by Mykhaylo Petrychuk

2015 International Conference on Noise and Fluctuations (ICNF), 2015

We present results of a comprehensive study of the liquid-back gate coupling effect in our Si nan... more We present results of a comprehensive study of the liquid-back gate coupling effect in our Si nanowire (NW) field-effect transistor (FET) structures using noise spectroscopy in different operation modes, including variable back-gate voltage. The constant channel resistance regime was used for measurements of the transport and noise properties of the liquid-gated Si NW FETs and simulations using Sentaurus TCAD software to improve our understanding of the coupling effect phenomena. The concentration profiles were simulated for different liquid- and back-gate voltages, which correspond to the experimental working points. The noise spectra were studied while tuning the position of the conducting channel in the liquid-gated Si NW FET. Results demonstrate that the dominant flicker noise mechanism in such structures is the number fluctuations due to the localization of the conducting channel near the dielectric layer of the liquid gate.

Nanotechnology, 2013

We report on the influence of low gamma irradiation (10 4 Gy) on the noise properties of individu... more We report on the influence of low gamma irradiation (10 4 Gy) on the noise properties of individual carbon nanotube (CNT) field-effect transistors (FETs) with different gate configurations and two different dielectric layers, SiO 2 and Al 2 O 3. Before treatment, strong generation-recombination (GR) noise components are observed. These data are used to identify several charge traps related to dielectric layers of the FETs by determining their activation energy. Investigation of samples with a single SiO 2 dielectric layer as well as with two dielectric layers allows us to separate traps for each of the two dielectric layers. We reveal that each charge trap level observed in the side gate operation splits into two levels in top gate operation due to a different potential profile along the CNT channel. After gamma irradiation, only reduced flicker noise is registered in the noise spectra, which indicates a decrease of the number of charge traps. The mobility, which is estimated to be larger than 2x10 4 cm 2 V-1 s-1 at room temperature, decreases only slightly after radiation treatment demonstrating high radiation hardness of the CNTs. Finally, we study the influence of Schottky barriers at the metal-nanotube interface on the transport properties of FETs analyzing the behavior of the flicker noise component.

Advanced Materials Interfaces

The transport and noise properties of fabricated, high‐performance, gate‐all‐around silicon liqui... more The transport and noise properties of fabricated, high‐performance, gate‐all‐around silicon liquid‐gated nanowire field‐effect transistor devices are investigated in different concentrations of MgCl2 solutions. The critical concentration of MgCl2 solution for charge inversion at the solid‐liquid interface is verified using noise spectroscopy and confirmed using the capacitance‐voltage measurement technique. In this study, it is found that the Hooge parameter (αH) and the equivalent input noise (SU) can effectively reflect the ion behavior on the surface of the nanowire. Moreover, the noise curves for αH and SU indicate two turning points at concentrations of 10−4 and 10−1 m for a peak and a valley, respectively. The noise transformation is related to the behavior of ions near the solid‐liquid interface in solutions with different MgCl2 concentrations is revealed. The results show that noise spectroscopy is a powerful method for monitoring charge dynamic processes in the research fie...

Composites Science and Technology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Ukrainian Journal of Physics, 2022

У данiй роботi представлено результати дослiдження електричних властивостей плiвок нових тернарни... more У данiй роботi представлено результати дослiдження електричних властивостей плiвок нових тернарних нанокомпозитiв дiелектричного полiмеру полiвiнiлiденфториду (ПВДФ), провiдного полiмеру полiанiлiну, допованого додецилбензолсульфоновою кислотою (ПАНI), з рiзним вмiстом мультистiнних вуглецевих нанотрубок (МСВНТ). На основi результатiв дослiджень електричного опору нанокомпозитiв у широкому iнтервалi температур 4,2–300 К показано, що при низьких температурах для нанокомпозитiв iз вмiстом МСВНТ 0–15 мас.% перенесення електричних зарядiв вiдбувається за рахунок тунелювання носiїв заряду мiж локалiзованими станами вiдповiдно до механiзму стрибкової провiдностi зi змiнною довжиною стрибка R ∼ exp[(T0/T)1/2]. Встановлено, що величина характеристичної температури T0 i температурний iнтервал стрибкової провiдностi залежать вiд вмiсту МСВНТ. Збiльшення вмiсту МВСНТ у плiвках нанокомпозитiв вiд 0–15 мас.% приводить до зменшення характеристичної температури T0 на два порядки i звуження темпера...

$Research paper thumbnail of Features of Formation and Transformation of Fe$_{3}$O$_{4}$-Nanoparticle Clusters in a Magnetic Fluid under the Long-Term Magnetic-Field Pulse Action$

METALLOFIZIKA I NOVEISHIE TEKHNOLOGII, 2017

Îòòèñêè äîñòóïíû íåïîñðåäñòâåííî îò èçäàòåëÿ Ôîòîêîïèðîâàíèå ðàçðåøåíî òîëüêî â ñîîòâåòñòâèè ñ ëè... more Îòòèñêè äîñòóïíû íåïîñðåäñòâåííî îò èçäàòåëÿ Ôîòîêîïèðîâàíèå ðàçðåøåíî òîëüêî â ñîîòâåòñòâèè ñ ëèöåíçèåé 2017 ÈÌÔ (Èíñòèòóò ìåòàëëîôèçèêè èì. Ã. Â. Êóðäþìîâà ÍÀÍ Óêðàèíû) Íàïå÷àòàíî â Óêðàèíå.

2013 22nd International Conference on Noise and Fluctuations (ICNF), 2013

Thin conducting gold films with nanoconstriction are characterized by noise spectroscopy with and... more Thin conducting gold films with nanoconstriction are characterized by noise spectroscopy with and without a single 1,4-benzenedithiol (BDT) molecule between the contacts. The low frequency noise spectral density demonstrates the 1/f α type behavior with a factor, α, near to 1. It is shown, that the normalized noise spectral density is proportional to the resistance R in power 3/2 for the case without a molecule as well as with a molecule. The experimental findings are in good agreement with theoretically predicted results. The results obtained are interpreted in terms of the fine tuning and evolution of structures with a nanoconstriction region. Structures with a single molecule demonstrate a lower noise level compared with the structures without it. Our results are promising for the development of nanostructures for future molecular electronics, functioning at room temperature.

The influence of the cyclic heating and cooling on properties of the aggregates (aka "ferrof... more The influence of the cyclic heating and cooling on properties of the aggregates (aka "ferrofluid clusters") in a ferrofluid, which made on the basis of magnetite nanoparticles, are investigated. The heating of the ferrofluid layer with such aggregates leads to equalization of the concentration between high- and low-concentrated phases. The temperature of the equalization of the phase concentrations was determined at different values of an external constant magnetic field, which was applied parallel to the layer of the ferrofluid. The temperature of the destruction of a periodic structure of the magnetic aggregates, which were formed during cooling of a homogeneous phase of the ferrofluid, was obtained at the different values of the applied external magnetic field.

Proceedings of the IEEE 21st International Conference on Noise and Fluctuations, ICNF 2011, 2011

ABSTRACT We report results of noise spectroscopy of field-effect transistors (FETs) fabricated ba... more ABSTRACT We report results of noise spectroscopy of field-effect transistors (FETs) fabricated based on individual carbon nanotube (CNT) using back-gate topography. The registered noise spectra allow us to estimate the numbers of carriers in working point with maximal transconductance. Lorentzian-shape noise components were analyzed in wide temperature range. The analysis enables us to find the energy, position and concentration of traps in the CNT-FET structures.

International Journal of High Speed Electronics and Systems, 2004

Transport and low frequency noise properties of undoped AlGaN/GaN high electron mobility transist... more Transport and low frequency noise properties of undoped AlGaN/GaN high electron mobility transistor (HEMT) heterostructures with 33% and 75% Al mole fractions in the ohmic and non-linear regimes of applied voltages are studied. In contrast to the low Al mole fraction, the noise properties of 75 % content structures are not affected by passivation. At small voltages both kinds of structures demonstrate about the same level of l/f excess noise. Deviations from conventional flicker noise were observed at high applied voltages. Additionally, differences in noise behaviour between the two structures were revealed. In the 75% content structures, a noise level suppression was registered in the non-linear regime, which is important for the development of low noise oscillator circuits.

physica status solidi (c), 2006

Low-frequency noise in AlGaN/GaN high electron mobility transistor (HEMT) heterostructures with a... more Low-frequency noise in AlGaN/GaN high electron mobility transistor (HEMT) heterostructures with additional AlN thin barrier layer is investigated. Transmission line model structures with different lengths of the conducting channel formed by polarization effects at the heterointerface of undoped AlGaN/AlN/GaN layers are studied. The measured noise demonstrates an unusual broadening of the generationrecombination components of the spectra. To explain the noise behaviour of the structure we consider a model taking into account peculiarities of the band structure of the interface with inserted AlN high molar fraction barrier layer.

2017 International Conference on Noise and Fluctuations (ICNF), 2017

GaN-based nanoribbons (NRs) represent important structures because of their unique transport prop... more GaN-based nanoribbons (NRs) represent important structures because of their unique transport properties. They have high breakdown voltage and can be scaled down to nanosizes. We studied the transport and noise properties of NRs in a wide temperature range applying different external treatments: ultraviolet (UV) excitation and high voltage bias. Characteristic features in the form of bumps were revealed in the temperature dependences of conductivity. The effect becomes more pronounced with decreasing NR width. Such exceptional behavior is related to a contribution of depletion regions at the edges of the NR to the sample conductivity. Characteristic energies of the deep traps in NR structures were obtained using generation-recombination components of measured noise spectra. Noise spectroscopy provides information about dynamic processes in structures. Depletion effects in AlGaN/GaN nanoribbons can be controlled using external UV excitation and applied electric fields. The results are...

2008 7th International Caribbean Conference on Devices, Circuits and Systems, 2008

We present a systematic study of the impact of layer structure design on the channel temperature ... more We present a systematic study of the impact of layer structure design on the channel temperature of AlGaN/GaN high electron mobility transistor (HEMT) structures. Device layer structures have been optimized to obtain minimum overheating temperature at high dissipated power in channel of HEMTs grown on different substrates. It is shown that temperature increase has opposite dependence on buffer thickness for sapphire and SiC substrates. Noise spectroscopy is also used to monitor the self-heating effect. Moreover, it is shown that the room temperature spectra can be used to determine the activation energy of the traps. An irreversible improvement in mobility is registered after irradiation of AlGaN/GaN heterostructures at a total dose 1x10 6 rad of 60 Co gamma rays. I.

Junctionless p+-p-p+ silicon nanowire (NW) field-effect transistors with various geometries were ... more Junctionless p+-p-p+ silicon nanowire (NW) field-effect transistors with various geometries were fabricated. Noise measurements were performed for the samples with different widths and in different operation modes. Results demonstrate significant changes in noise and Hooge parameter when the NW geometry is changed. The dependences obtained can be explained by considering the different impacts of the top and two side silicon oxide interfaces formed on the nanowire walls. According to the fabrication process, where anisotropic wet etching was used, almost atomic flat side wall surfaces make a smaller contribution to the noise compared to top walls in NWs of different widths. This effect results in a decreased noise level in NW FETs of smaller NW widths, operating in a weak accumulation regime. The effects thus revealed are important for improving the signal-to-noise ratio in liquid-gated biosensors.

MRS Proceedings, 2002

In this work we present steady-state characteristics and low-frequency noise spectra of AlGaN/GaN... more In this work we present steady-state characteristics and low-frequency noise spectra of AlGaN/GaN based high electron mobility transistors (HEMTs) exposed to gamma ray radiation. The devices with a variety of gate length (150-350 nm) and width (100-400 νm) were irradiated by 60Co gamma rays with doses in the range of 104-109 Rad and flux of 102 Rad/s. Dose dependencies of basic operating parameters of the transistors, such as saturation current (Isat), transconductance (gm), channel conductance (gc), and threshold voltage (VT) are analysed. Our study show that visible changes of above mentioned parameters are observed under relatively small doses (105 Rad) and strongly depend on the HEMT's topology. The transconductance decreases and threshold voltage becomes more negative for all devices while deviation of these parameters from its initial values does not exceed 20% at highest irradiation dose. At the same time variation of the channel conductance as well as saturation current ...

International Semiconductor Device Research Symposium, 2003

In this paper, we presented results of steady state and pulse measurement of AlGaN/GaN heterostru... more In this paper, we presented results of steady state and pulse measurement of AlGaN/GaN heterostructures up to ultra high electric fields accompanied by low frequency noise measurements. Hot electron relaxation process were analysed. The contact resistance was measured in low field (ohmic) region and taken into account when calculating the average electric field. The velocity-field characteristics in AlGaN/GaN heterostructures obtained by measurement of the current-voltage characteristics. The spectra of the normalised current noise for different values of electric field E measured at T=300 K for the device with channel length of 25 μm and width of 100 μm is studied through experimental results.

2013 22nd International Conference on Noise and Fluctuations, ICNF 2013, 2013