Tymoteusz Ciuk

Łukasiewicz Research Network - Institute of Microelectronics and Photonics · SiC Technologies Research Group

High-temperature electrical properties of p-type hydrogen-intercalated quasi-free-standing epitaxial Chemical Vapor Deposition graphene on semi-insulating vanadium-compensated on-axis 6H-SiC(0001) and high-purity on-axis 4H-SiC(0001) originate from the double-carrier system of spontaneous-polarization-induced holes in graphene and thermally activat...

In this letter, we demonstrate a Hall effect sensor in the technology of amorphous-Al2O3-passivated transfer-free p-type hydrogen-intercalated quasi-free-standing epitaxial Chemical Vapor Deposition graphene on semi-insulating high-purity on-axis 4H-SiC(0001), pre-epitaxially modified with 5- keV hydrogen (H+) ions. The sensor operates between 305...

Kelvin Probe Force Microscopy is a method to assess the contact potential difference between a sample and the probe tip. It remains a relative tool unless a reference standard with a known work function is applied, typically bulk gold or cleaved highly oriented pyrolytic graphite. In this report, we suggest a verifiable, two-dimensional standard in...

We demonstrate a genuine method for three-dimensional pictorial reconstructions of two-dimensional, three-dimensional, and hybrid specimens based on confocal Raman data collected in a back-scattering geometry of a 532-nm setup. The protocol, or the titular PRISM (Phase-Resolved Imaging Spectroscopic Method), allows for sub-diffractive and material-...

This article reveals a unique self-healing ability of the amorphous-aluminum-oxide-passivated p-type hydrogenintercalated quasi-free-standing epitaxial Chemical Vapor Deposition graphene on semi-insulating vanadiumcompensated nominally on-axis 6H-SiC(0001) system, exposed for 166 h to a destructive flux of 3.3 × E11 cm−2s−1 of mostly fast-neutrons...

The protocol, or the titular PRISM (Phase-Resolved Imaging Spectroscopic Method), allows for sub-difractive and material-resolved imaging of the object’s constituent material phases. The spacial component comes through either the signal distal attenuation ratio (direct mode) or subtle light-matter interactions, including interference enhancement an...

For the first time, the Z1 and Z2 defects with closely spaced energy levels having negative-U properties are revealed in high-purity semi-insulating (HPSI) 4H-SiC using Laplace-transform photoinduced transient spectroscopy (LPITS). In this material, after switching off the optical trap-filling pulse, either the one-electron or the two-electron ther...

The production and verification of microwave absorbers are a subject of high priority. These are due to the fast development of telecommunication technologies and the need to reduce electromagnetic pollution. Such materials are implementable in multiple industries, including military, medical, and laboratory equipment. One should remember that the...

Graphene flow sensors not only hold great prospects for applications but also encounter many difficulties, such as unwanted electrochemical phenomena, low measurable signal, and limited dependence on the flow direction. This study proposes an approach allowing for the detection of a flow direction-dependent electric signal in aqueous solutions of s...

Each material has a unique intrinsic vibrational structure. Thanks to the phenomena of interaction of light with this structure, Raman spectroscopy using this phenomenon is a kind of "fingerprint" of a given material. Direct analysis makes it possible to unambiguously distinguish between different materials. An in-depth study of the Raman signal a...

In this report, we present transfer-free p-type hydrogen-intercalated quasi-free-standing epitaxial Chemical Vapor Deposition graphene on 15-mm × 15-mm semi-insulating vanadium-compensated on-axis 6H–SiC(0001), characterized in that its room-temperature direct-current Hall-effect-derived hole mobility 𝜇p = 5019 cm2/Vs, and its statistical number of...

Exploiting a number of subtle interactions of light with matter allows the development of sophisticated methods. On of these interactions, the phenomenon of inelastic Raman scattering, makes it possible to identify and separate layers in parallel, even seemingly hidden ones.

We demonstrate a protocol for layer-resolved Raman imaging and analysis of Chemical Vapor Deposition graphene grown on copper foil an transferred onto an oxidized silicon substrate.

Graphene flow sensors hold great prospects for applications, but also encounter many difficulties, such as unwanted electrochemical phenomena, low measurable signal and limited dependence on the flow direction. This study proposes a novel approach allowing for the detection of a flow direction-dependent electric signal in aqueous solutions of salts...

Modern two-dimensional carbon materials are being increasingly studied as potential magnetic field sensors for use in environments with harmful radiation, such as neutron radiation present in future fusion reactors. Potential radiation resistance is also demonstrated by classical semiconductor thin-film materials, after appropriate doping. A necess...

In this report, we demonstrate an applied protocol for layer-resolved Raman imaging and analysis of undesirable ad-layers found in Chemical Vapor Deposition graphene grown on copper foil and transferred onto an oxidized silicon substrate. The method assumes that the intensity of the silicon-related Raman-active mode at 520 cm⁻¹ is attenuated by 2.3...

Mechanism of the "shadow method" using transferred graphene as an example.

In this work, we report study on the impact of neutron radiation on quasi-free-standing (QFS) graphene [1]. For this purpose, we have fabricated hydrogen-intercalated QFS graphene on semiinsulating high-purity 4H-SiC (0001) [2], passivated with an Al2O3 layer [3], and exposed it to a fast-neutron fluence of ≈ 6.6 x 10^17 cm^-2. The result have show...

The ability to precisely measure magnetic fields under extreme operating conditions is becoming increasingly important as a result of the advent of modern diagnostics for future magnetic confinement fusion devices. These conditions are recognized as strong neutron radiation and high temperatures (up to 350 °C). We report on the first experimental c...

In this report, we introduce a novel method based on low-frequency noise analysis for the assessment of quality and pattern of inhomogeneity in intentionally-aged Hall effect sensors featuring hydrogen-intercalated quasi-free-standing epitaxial Chemical Vapor Deposition graphene mesa on semi-insulating high-purity on-axis 4H-SiC(0001), all passivat...

In this paper, we report on the first experimental study on the impact of neutron radiation on quasi-free-standing (QFS) graphene. For this purpose, we have fabricated hydrogen-intercalated QFS graphene on semiinsulating high-purity 4H-SiC(0001), passivated it with an Al2O3 layer,and exposed it to a fast-neutron fluence of ≈6.6×1017 cm⁻². The resul...

In this report, we demonstrate a method for the enhancement of Raman active modes of hydrogen-intercalated quasi-free-standing epitaxial chemical vapor deposition graphene and the underlying semi-insulating 6H–SiC(0001) substrate through constructive signal interference within atomic-layer-deposited amorphous Al2O3 passivation. We find that an opti...

Fabrication and modification of flake graphene is one of the most important R&D field at Łukasiewicz - Institute of Microelectronics and Photonics. We are capable of producing manifold forms of graphene-based materials, including: graphene oxide, reduced graphene oxide, two-stage reduced graphene oxide, graphene from direct exfoliation, functionali...

In this report we demonstrate a method for direct determination of the number of layers of hydrogen-intercalated quasi-free-standing epitaxial Chemical Vapor Deposition graphene on semiinsulating vanadium-compensated on-axis 6H-SiC(0001). The method anticipates that the intensity of the substrate’s Raman-active longitudinal optical A1 mode at 964 c...

Łukasiewicz Research Network – Institute of Microelectronics and Photonics has been developing the construction and technology of an innovative graphene-based magnetic field sensor that utilizes the classical Hall effect to convert magnetic field into a useful voltage signal. The sensor is based on hydrogen-intercalated quasi-free-standing graphen...

The great interest in graphene applications in optics and optoelectronics still requires alternative methods for obtaining high-quality graphene. Currently used methods are based on graphene transfer onto a target substrate. As a consequence, the structural quality of graphene is lowered and so are its the electrical and optical properties. What is...

In this report we investigate structural and electrical properties of epitaxial Chemical Vapor Deposition quasi-free-standing graphene on an unintentionally-doped homoepitaxial layer grown on a conducting 4H-SiC substrate 4° off-axis from the basal [0001] direction towards [11-20]. Due to high density of SiC vicinal surfaces the deposited graphene...

The structure of magnetoresistance curves as a function of magnetic field from 0 to 14 T at temperatures from 0.4 to 6.0 K for macroscopic samples of the quasi-free-standing (QFS) graphene monolayer on SiC substrate, are observed and analyzed, and also the spatial and depth frequency distribution of phonons have been measured using the micro-Raman...

State-of-the-art secondary ion mass spectrometry (SIMS), X-ray reflectivity (XRR) and atomic force microscopy (AFM) have been used to determine the effect of oxidation temperature on the inhomogeneity of chemical composition...

Graphene has attracted huge attention due to its unique electronic properties, however, when supported those are significantly dependent on the interface interactions. One of the methods of decoupling graphene sheets from a substrate is hydrogen intercalation, which has been shown to produce quasi-free-standing (QFS) layers on a SiC (0001) surface....

We present an overview of the main techniques for production and processing of graphene and related materials (GRMs), as well as the key characterization procedures. We adopt a ‘hands-on’ approach, providing practical details and procedures as derived from literature as well as from the authors’ experience, in order to enable the reader to reproduc...

ŁUKASIEWICZ - ITME offers two types of graphene-based Hall effect sensors operating both at low (80 K) and at very high temperatures (770 K). Possible applications include brushless motors (BLDC and PMSM) and electric current transducers for power usage monitoring.

Lukasiewicz Research Network – ITME has had many years of experience in silicon carbide homoepitaxy on conducting up to 3-in 4H-SiC substrates. The growth technology covers unintentionally doped layers, n-type layers and p-type layers. Surface etched pit density is below 7000 cm-2 for a substrate that is 4° off-axis from the (0001) plane towards th...

Semiconductor devices based on silicon carbide play an important role as components for power electronic systems. Nowadays it's recognized that at least 50 percent of electricity distribution all over the world is controlled by such elements. It's also expected that within a decade, the power devices' share in electricity conversion will rise from...

In this report, we demonstrate a novel high-temperature Hall effect sensor that is based on quasi-free-standing monolayer graphene epitaxially grown on high-purity semiinsulating (SI) on-axis 4H-SiC(0001) substrate in a chemical vapor deposition process. To ensure statistical perspective, characteristics of 23 elements are determined as a function...

We present an overview of the main techniques for production and processing of graphene and related materials (GRMs), as well as the key characterization procedures. We adopt an "hands-on" approach, providing practical details and procedures as derived from literature as well as from the authors' experience, in order to enable the reader to reprodu...

The physics of nonlinear-optical refraction in graphene has remained unclear for almost a decade now. We solve this issue through self-phase modulation experiments in graphene-covered waveguides, revealing the extra-ordinary free-carrier interactions that underpin the refraction process.

This paper presents recent progress in the development of the new type of Hall-effect sensor with the graphene layer acting as sensing material. Newly developed Hall-effect sensor is made of quasi-free-standing bilayer graphene structure. The graphene structure is placed inside the standard QFN-32 package for integrated circuits and mounted on the...

Applying graphene in optical and photonic applications is anticipated to be a promising strategy to attain new technological functionalities. To maximize the exploitation of graphene’s extraordinary optical properties, precise control over its Fermi level will be of vital importance. Therefore, chemical doping is a viable approach to manipulate gra...

Graphene is considered a record-performance nonlinear-optical material on the basis of numerous experiments. The observed strong nonlinear response ascribed to the refractive part of graphene's electronic third-order susceptibility χ(3) cannot, however, be explained using the relatively modest χ(3) value theoretically predicted for the 2D material....

We solve the long-standing discrepancy between the theoretically predicted and experimentally observed performance of nonlinear-optical refraction in graphene. Hereto we study self-phase modulation in silica-core waveguides covered with graphene.

The paper describes the design, development and investigation of a new type of Hall-effect sensors of a magnetic field made of graphene. The epitaxial growth of high-quality graphene structures was performed using a standard hot-wall CVD reactor, which allows for easy integration with an existing semiconductors production technologies. The function...

This letter presents the design, fabrication and characterization of the first graphene based monolithic microwave integrated circuit (MMIC) in microstrip technology operating in W-band. The circuit is a resistive mixer in a 250 nm graphene field effect transistor (G-FET) technology on a SiC substrate. A conversion loss of 18 dB is achieved which i...

In this report, we demonstrate the preparation method of a multi-layer stack with a pre-defined number of graphene layers, which was obtained using chemical vapor deposition graphene deposited on a copper substrate and subsequently transferred onto a poly(methyl methacrylate) (PMMA) substrate. The prepared multi-layer stack can also be transferred...

We experimentally demonstrate a negative Kerr nonlinearity for quasi-undoped graphene. Hereto, we introduce the method of chirped-pulse-pumped self-phase modulation and apply it to graphene-covered silicon waveguides at telecom wavelengths. The extracted Kerr-nonlinear index for graphene equals n2,gr = -10^(-13) m^2/W. Whereas the sign of n2,gr tur...

Controllable chemical doping of graphene has already proven very useful for electronic applications, but when turning to optical and photonic applications, the additional requirement of having both a high transparency and a low surface roughness has, to our knowledge, not yet been fulfilled by any chemical dopant system reported so far. In this wor...

We experimentally demonstrate a negative Kerr nonlinearity for quasiundoped graphene. Hereto, we introduce the method of chirped-pulse-pumped self-phase modulation and apply it to graphene-covered silicon waveguides at telecom wavelengths. The extracted Kerr-nonlinear index for graphene equals n2,gr=−10^(−13) m^2/W. Whereas the sign of n2,gr turns...

In recent years the integration of graphene into silicon photonics has attracted much attention as it allows using well-established CMOS technology for constructing next-generation photonic integrated circuits. Because of graphene's extraordinary optical properties, the deposition of graphene on top of silicon photonic chips can further enhance the...

In this report, we demonstrate a complete Hall effect element that is based on quasi-free-standing monolayer graphene synthesized on a semi-insulating on-axis Si-terminated 6H-SiC substrate in an epitaxial Chemical Vapor Deposition process. The device offers the current-mode sensitivity of 87 V/AT and low excess noise (Hooge&apos;s parameter αH <...

We present the use of femtosecond laser ablation for the removal of monolayer graphene from silicon-on-insulator (SOI) waveguides, and the use of oxygen plasma etching through a metal mask to peel off graphene from the grating couplers attached to the waveguides. Through Raman spectroscopy and atomic force microscopy, we show that the removal of gr...

We demonstrate the demodulation of a multi-Gb/s ON-OFF keying (OOK) signal on a 96 GHz carrier by utilizing a 250-nm graphene field-effect transistor as a zero bias power detector. From the eye diagram, we can conclude that the devices can demodulate the OOK signals up to 4 Gb/s.

In the paper, the process of manufacturing the graphene Hall-effect structure is presented. Moreover, the measurement system utilizing Helmholtz coils as a source of reference magnetic field is described. The basic functional properties of developed sensor, like sensitivity and offset voltage, were investigated. Also the influence of the supply cur...

We present a new approach to remove monolayer graphene transferred on top of a silicon-on-insulator (SOI) photonic integrated chip. Femtosecond laser ablation is used for the first time to remove graphene from SOI waveguides, whereas oxygen plasma etching through a metal mask is employed to peel off graphene from the grating couplers attached to th...

Graphene is one of the most promising materials for application in electronics. It has been recently discovered that on certain substrates graphene is characterized by a rather strong spin-orbit interaction, which is valuable to spintronics applications. In this paper we present an application of a system for measuring of graphene's electrical para...

Paper presents the results of investigation of the temperature influence on the basic functional properties of graphene Hall-effect sensors. The measurement system utilizing Helmholtz coils as a source of external magnetic field and environmental chamber for setting temperature was developed. Two types of monolayer graphene structures grown on both...

Paper presents the results of investigation of the influence of protective layer on the basic functional properties of experimental graphene Hall-effect sensors. Both monolayer and bilayer type of graphene structure was investigated under external magnetic field. Measurement system for obtaining U H(B) characteristics of Hall-effect sensors was dev...

We show that monolayer graphene can be grown isothermally on polycrystalline copper foils via ultra-high vacuum chemical vapor deposition (UHV-CVD), using acetylene as a carbon precursor. The growth is self-limiting, yielding monolayer graphene with a quality comparable to that of graphene grown by atmospheric- or low-pressure chemical vapor deposi...

We report on attempts to produce a graphene based liquid flow sensor. Our results indicate that modifications of the electric double layer, formed in the vicinity of the graphene surface, dominate over mechanisms responsible for liquid flow-induced voltage/current generation. Several graphene structures were tested in different measurement configur...

The transport properties of quasi-free-standing (QFS) bilayer graphene on SiC depend on a range of scattering mechanisms. Most of them are isotropic in nature. However, the SiC substrate morphology marked by a distinctive pattern of the terraces gives rise to an anisotropy in graphene's sheet resistance, which may be considered an additional scatte...

A sapphire rod resonator operating at microwave frequencies was used to determine the electric properties of 600 nm thick YBCO films in the superconducting state. The rigorous electromagnetic modelling was applied to transform the measured Q-factor and the resonant frequency to the complex conductivity of high accuracy, which was previously shown t...

Paper presents the results of the hall effect testing in the graphene structures. Special hall effect structures were designed and build, using large graphene sheets. Laboratory testing stand was developed to test sensitivity and offset voltage in hall effect structures under external magnetic field. Characteristics of investigated structures were...

We report on the electrical characterization and Raman spectroscopy of chemical vapor deposition copper-grown graphene transferred onto a Si/SiO2 substrate by high-speed (1 mm/s) electrochemical delamination. We determine graphene’s sheet resistance, carrier mobility, and concentration as well as its physical quality as a function of the electolyte...