DIVISION of SURFACE PHYSICS and NANOTECHNOLOGY

@conference{PUTSTEM2026_KK,

title = {An experimental study of bulk HfS2, ZrS2 and HfSe2 monocrystal surfaces exposed to ambient air},

author = {Katarzyna Kwiecień and Piotr Kałuziak and Jan Raczyński and Agnieszka Puchalska and Anna Dychalska and Edyta Chłopocka and Dawid Kot and Łukasz Majchrzycki and Mirosław Szybowicz and Leszek Jurczyszyn and Mariya V. Dobrotvorska and Mikołaj Lewandowski and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2026/05/PUTSTEM2026_KK.pdf},

year  = {2026},

date = {2026-05-15},

urldate = {2026-05-15},

booktitle = {PUT STEM DAY 2026},

address = {Poznań, May 15},

abstract = {HfS2, ZrS2, and HfSe2 belong to the group IV transition metal dichalcogenides (TMDs). These materials are promising for next-generation electronics due to their tunable band gaps (1–2 eV) and high

predicted carrier mobilities at room temperature. While many TMDs are chemically inert, group IV TMDs oxidize when exposed to air. Understanding how this oxidation affects their physical properties and

surface morphology is critical for their use in electronic devices. In this study, we investigate bulk HfS2 and ZrS2 monocrystals exposed to ambient air and compare our findings to the observations we made for the oxidized HfSe2. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images reveal clear differences in surface morphology: HfSe2 develops characteristic selenium-rich blisters, while the sulfur-based TMDs (HfS2 and ZrS2) show the formation of pits with electronic and mechanical properties that differ from those of the surrounding area. Further Raman spectroscopy data reveals that HfSe₂ vibrational modes change rapidly due to the ambient air exposure of the material, whereas the vibrational properties of HfS2 and ZrS2 remain stable. Finally, Xray photoemission spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX) show that the sulfur-based TMDs are significantly more chemically stable in ambient air than HfSe2. These results offer a comprehensive description of the surface oxidation of chosen TMDs, which is crucial in the context of the material selection and technological processing requirements for future group IV TMD-based devices.



Funding from the Ministry of Science and Higher Education under project no. 0512/SBAD/6220.

Funding from the Ministry of Science and Higher Education under project no. 0512/SBAD/2620.},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{PUTSTEM2026_WR,

title = {High-field galvanomagnetic response of graphene and InSb-based hallotrons},

author = {Wiktoria Reddig and Piotr Kałuziak and Agnieszka Żebrowska and Marta Przychodnia and Tymoteusz Ciuk and Karolina Piętak-Jurczak and Maciej J. Szary and Jan Raczyński and Wojciech Koczorowski and Semir El-Ahmar},

url = {https://nano.put.poznan.pl/wp-content/uploads/2026/05/PUTSTEM2026_WR.pdf},

year  = {2026},

date = {2026-05-15},

urldate = {2026-05-15},

booktitle = {PUT STEM DAY 2026},

address = {Poznań, May 15},

abstract = {Emerging technologies such as fusion energy systems and space applications increasingly demand electronic components capable of stable and predictable operation in multi-tesla magnetic fields over wide

temperature ranges. Semiconductor Hall devices, particularly those based on InSb, are widely used in demanding conditions due to their high carrier mobility and sensitivity. Controlled donor doping enables

stabilization of electrical properties over broad temperatures. However, it simultaneously alters intrinsic transport properties and introduces trade-offs between sensitivity, thermal stability, and reproducibility. As

a result, device performance may deviate from ideal behavior in strong magnetic fields. These limitations motivate the exploration of alternative materials for robust magnetic-field sensing, with graphene emerging as a promising candidate. In this work, we present a comparative study of galvanomagnetic properties of two types of deviceready Hall sensor platforms: (i) p-type hydrogen-intercalated quasi-free-standing epitaxial graphene grown on 4H-SiC(0001) passivated with an Al2O3, and (ii) heavily donor-doped InSb thin film deposited on semi-insulating GaAs substrate and protected with dielectric layer. Both device types were integrated into CERDIP8 ceramic housing, ensuring suitability for operation in harsh environments. InSb structures with different doping levels were analysed to show the impact of transport properties on electrical response in strong magnetic field. The galvanomagnetic response was investigated in magnetic fields up to 11 T at room temperature and under liquid-helium conditions. The graphene-based devices exhibit a monotonic and nearly linear Hall response across the full magnetic-field range, indicating weak magnetoresistive effects. In contrast, InSbbased sensors, due to intense doping, display significant nonlinearity and distortion in the transverse voltage at high magnetic fields. This effect originates from strong magnetoresistance, where the rapid increase of longitudinal resistance leads to mixing between longitudinal and transverse voltage components, distorting the Hall signal [4]. As a result, the usable magnetic-field range of semiconductor Hall devices becomes limited in the multi-tesla regime. The results demonstrate that graphene Hall devices maintain superior stability of response under high magnetic field and cryogenic conditions. These findings highlight graphene as a promising material platform for reliable magnetic-field sensing in extreme environments where conventional semiconductorbased Hall sensors, such as InSb, may face intrinsic limitations.



Funding from the Ministry of Science and Higher Education under project no. 0512/SPHD/2501.

Funding from the Ministry of Science and Higher Education under project no. 0512/SBAD/2620.

Funding from National Centre for Research and Development under Grant Agreement No. LIDER/8/0021/L-11/19/NCBR/2020.},

note = {Poster presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{PUTSTEM2026_JR,

title = {Thermally Induced Correlation Effects in metal/PtSe2 heterostructures studied by Raman Spectroscopy},

author = {Jan Raczyński and Michał Szczęsny and Semir El-Ahmar and Edyta Chłopocka and Mirosław Szybowicz and Dawid Kot and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2026/05/PUTSTEM2026_MS.pdf},

year  = {2026},

date = {2026-05-15},

booktitle = {PUT STEM DAY 2026},

address = {Poznań, May 15},

abstract = {We present a systematic study of interfacial physics in meta/PtSe2 heterostructures (metal = Ti, Cr, Ni, Pd, Pt) employing temperature-dependent Raman spectroscopy (RT–473 K) and SEM imaging. The deposition of metallic overlayers with thicknesses of 10 and 15 nm results in a pronounced narrowing of phonon linewidths (up to 50%) and a significant increase in the IA1g/IEg intensity ratio compared to bulk PtSe2. These effects are attributed to dielectric screening and work-function-dependent charge redistribution. An analysis of the relationship between the Eg and A1g phonon modes indicates that the introduction of metallic layers leads to the onset of compressive strain and charge carrier doping. At the same time, the inherent anharmonic behaviour of the lattice captured by the temperature-dependent coefficients remains largely unaffected and closely matches that observed in bulk PtSe₂. Furthermore, although annealing triggers metaldependent morphological modifications, the core vibrational properties of the PtSe2 lattice remain essentially unchanged. These findings provide insight into the electronic and mechanical coupling at metal–2D interfaces and highlight PtSe2 as a robust platform for stable two-dimensional electronic applications.},

note = {Poster presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{NEA_GF2025,

title = {Toward Radiation-Hard Magnetic Diagnostics: Testing Graphene Sensors for Tokamaks},

author = {Wiktoria Reddig and Semir El-Ahmar and Tymoteusz Ciuk and Rafał Prokopowicz},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/12/NEA_GF2025_WR.pdf},

year  = {2025},

date = {2025-12-11},

urldate = {2025-12-11},

booktitle = {NEA Global Forum Rising Stars Workshop},

address = {Stockholm, December 10-12},

abstract = {As the urgency of addressing climate change grows, nuclear fusion is becoming one of the most promising long-term energy solutions. In magnetic confinement fusion reactors (especially tokamaks) accurate measurement of magnetic fields is essential for monitoring and control. This research explores the potential of advanced graphene-based sensors for this purpose, focusing on their performance in the extreme neutron radiation and high temperatures environment found inside a fusion reactor. 

Hall-effect magnetic field sensors were manufactured in form of graphene grown on silicon carbide (SiC) and intercalated with a hydrogen layer. The sensors were coated with aluminium oxide for protection. These devices were then exposed to neutron radiation in the MARIA research reactor at Polish National Centre for Nuclear Research, and separately tested at high temperatures to simulate tokamak conditions. 

After irradiation, electrical measurements and material analysis techniques (like Raman characterisation, Transmission Electron Microscopy and Density Functional Theory calculations) were utilised to study how neutron radiation affected the sensors. They revealed that the radiation had a marginal impact on graphene layer. However some performance loss was observed and we attribute it to deterioration of the hydrogen layer, which plays a key role in maintaining graphene’s useful properties by separating it from the substrate. Interestingly, heating the sensors to temperatures above 200C helped partially restore their electrical properties, likely by allowing surface diffusion of

hydrogen on the surface of SiC. 

These results show that while neutron radiation can degrade sensor performance, some of the damage can be reversed with thermal treatment, though only to a certain radiation threshold. Understanding how radiation affects these materials will be crucial for developing reliable magnetic sensors that can operate inside future fusion reactors.},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{Zakopane25_PK,

title = {Surface Characterization of Thin-Layer Materials for Potential Applications in Physical Unclonable Functions},

author = {Piotr Kałuziak and Katarzyna Kwiecień and Jan Raczyński and Marek Nowicki and Łukasz Majchrzycki and Michał Szczęsny and Sylwester Gawinkowski and Daria Larowska-Zarych and Semir El-Ahmar and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/12/zakopane2025_PK.pdf},

year  = {2025},

date = {2025-11-28},

urldate = {2025-11-28},

booktitle = {XIII Workshop on Applications of Scanning Probe Microscopy – STM/AFM 2025},

address = {Zakopane, 26 - 30 Listopada},

abstract = {Two-dimensional (2D) materials and thin semiconductor films exhibit unique properties that make them attractive for applications in electronics, sensing, and information security. Here, we investigate selected layered systems to explore their potential for physical unclonable functions (PUFs), focusing on characteristic nanoscale features revealed by Raman spectroscopy, AFM, and SEM.

Continuous PtSe2films covered with gold nanoparticles were studied using surface-enhanced Raman spectroscopy (SERS), revealing enhanced vibrational signatures. Additionally, AFM measurements confirmed low roughness at the nanoscale morphology. Exfoliated ZrS2 flakes were analyzed by conventional Raman spectroscopy and AFM techniques, highlighting thickness variations and different degrees of surface oxidation properties that appear highly specific to the sample. Finally, chemically modified InSb layers examined with AFM and SEM showed surface roughness variations and etching-induced morphological changes. These results demonstrate that intrinsic disorder, film morphology, and surface modifications can generate unique and irreproducible features. The combined use of SERS, Raman spectroscopy, AFM, and SEM provides a comprehensive framework for evaluating the suitability of thin-layer materials as candidates for secure PUF schemes.



Funding from the Ministry of Science and Higher Education under project no. 0512/SBAD/6220.

Funding from the Ministry of Science and Higher Education under project no. 0512/SBAD/2520.},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{Zakopane25_MP,

title = {STM/STS studies of single-atom Fe inclusions in MBE-grown monolayer MoS2/Gr/Ir(111)},

author = {Marta Przychodnia and Alina Drechsler and Maciej Bazarnik and Anika Schlenhoff},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/12/zakopane2025_MP.pdf},

year  = {2025},

date = {2025-11-28},

urldate = {2025-11-28},

booktitle = {XIII Workshop on Applications of Scanning Probe Microscopy – STM/AFM 2025},

address = {Zakopane, 26 - 30 Listopada},

abstract = {Transition metal dichalcogenides (TMDs) have drawn significant attention due to their scalability and the thickness-dependence of their electronic density of states (DOS). Moreover, dimensionally confined TMDs, mainly 2D monolayers (MLs), are highly sensitive to structural defects, such as vacancies, interstitial and substituent atoms. Even in very low-density regimes, these impurities significantly affect various properties by introducing stress and/or modifying the DOS. Consequently, there are ongoing efforts to engineer defects in TMDs to tune their electronic, magnetic, optical, and catalytic properties. While most of the current research focuses on naturally occurring defects in chemical vapor deposited TMDs, to improve control over defect engineering, we focus on intentional single-atom inclusions in TMDs grown by molecular beam epitaxy (MBE).

In this presentation, I summarize our scanning tunneling microscopy (STM) and spectroscopy (STS) studies of Fe inclusions in ML MoS2 on Gr/Ir(111), which we realize by co-evaporating Fe during MoS2 MBE growth. We identify the Fe inclusions upon comparison with naturally occurring defects found on the undoped MoS2 grown previously in the same UHV chamber.  STS experiments reveal the presence of in-gap states arising from the incorporation of Fe atoms, whose spatial distributions are imaged by means of bias-dependent differential conductance mapping. Furthermore, resonant tunneling spectroscopy shows that the image potential states (IPS) are modified by the Fe inclusions, influencing the IPS’ energetic positions due to a variation in the local work function.



Funding from the Ministry of Science and Higher Education (Poland) within Project 0512/SBAD/2520.

},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{Zakopane25_WR,

title = {Radiation Resilience of Graphene Based Heterostructures Insights from Multimodal Structure Characterization},

author = {Wiktoria Reddig and Tymoteusz Ciuk and Maciej J. Szary and Jakub Jagiełło and Artur Dobrowolski and Rafał Prokopowicz and Marek Weiss and Marek Wzorek and Semir El-Ahmar},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/12/zakopane2025_WR.pdf},

year  = {2025},

date = {2025-11-27},

urldate = {2025-11-27},

booktitle = {XIII Workshop on Applications of Scanning Probe Microscopy – STM/AFM 2025},

address = {Zakopane, 26 - 30 Listopada},

abstract = {Enhancing the durability of magnetic field diagnostic electronics under fast-neutron irradiation requires materials capable of withstanding extreme defect formation. Dimensionality reduction offers a potential route, as two-dimensional systems inherently limit the development of collision cascades responsible for radiation damage in bulk materials. Graphene, with its two-dimensional nature and low neutron-collision cross section, embodies this concept. Yet, when integrated into a heterostructure, can

it maintain its intrinsic radiation resilience?

We explore the neutron radiation tolerance of an a-Al2O3/graphene/H-intercalated SiC(0001) heterostructure, combining reduced dimensionality with a conventional substrate platform. Using high-resolution transmission electron microscopy, Raman spectroscopy, electrical characterization and other techniques, we assess the material's structural and functional stability under fast-neutron fluences up to 2E18 n cm^-2 . Our findings show, the graphene layers exhibit negligible structural damage in comparison to bulk elements

Showing that graphene retains its structural integrity and electronic performance even under extreme neutron exposure, we suggest a viable route toward radiation-resilient sensor technologies. Such resilience is particularly crucial for future fusion energy systems, where long-term, reliable magnetic diagnostics will be key to successful reactor operation.



Funding from the Ministry of Science and Higher Education (Poland) for support under the project no. 0512/SBAD/2520. 

Funding from the 'PhDBoost' Program for doctoral students of the Doctoral School of Poznan University of Technology (in 2024) from the University's subsidyfinancedfrom the funds of Ministry of Science and Higher Education.},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{Zakopane25_KK,

title = {Comparative analysis of group IV bulk TMDs' surface stability under ambient conditions},

author = {Katarzyna Kwiecień and Piotr Kałuziak and Jan Raczyński and Agnieszka Puchalska and Anna Dychalska and Edyta Chłopocka and Dawid Kot and Mirosław Szybowicz and Leszek Jurczyszyn and Mariya V. Dobrotvorska and Mikołaj Lewandowski and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/12/zakopane2025_KK.pdf},

year  = {2025},

date = {2025-11-27},

booktitle = {XIII Workshop on Applications of Scanning Probe Microscopy – STM/AFM 2025},

address = {Zakopane, 26 - 30 Listopada},

abstract = {Group IV Transition Metal Dichalcogenides (TMDs) possess attractive electronic properties, such as a tunable band gap in the 1-2 eV range and predicted charge carrier mobilities in the thousands of cm^2 V^-1 s^-1. Unlike most TMDs, they are not chemically inert under ambient conditions. Oxidation can alter their surface properties and morphology, making it essential to study the changes as they impact technological processing of group IV TMDs and their performance in electronic devices. In our earlier work, we demonstrated that HfSe2 undergoes rapid oxidation, resulting in Se-rich blister formation, oxygen diffusion into the bulk of the crystal, and HfO2 growth on the surface. In this study, we extend our investigation to HfS2 and ZrS2, comparing the impact of ambient air exposure on their surfaces with that observed for HfSe2. Scanning electron microscopy (SEM) reveals morphological differences: while HfSe2 shows bright blister-like features, sulfides develop areas with different charge carrier concentration that gradually rise in number with increasing exposure time to ambient air. Raman spectroscopy (RS) indicates that the vibrational modes of HfS2 and ZrS2 remain mostly unaffected, suggesting higher chemical stability compared to HfSe2, whose RS modes change drastically as the surface oxidation progresses. Complementary X-ray photoemission spectroscopy (XPS) data describes the influence of the ambient air exposure on the investigated materials' surface chemical deposition. These results provide a comprehensive picture of the morphological and chemical differences in group IV TMD oxidation, highlighting the role of chemical composition in determining their surface stability, which affects their integration potential with silicon-based electronics.



Funding from of Ministry of Science and Higher Education under project no. 0512/SBAD/6220.

Funding from of Ministry of Science and Higher Education under project no. 0512/SBAD/2520.},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{PTP2025_SA,

title = {Grafen epitaksjalny w energetyce jądrowej: wyzwania i możliwości wsparte technikami próżniowymi},

author = {Semir El-Ahmar and Maciej J. Szary and Wiktoria Reddig and Jakub Jagiełło and Artur Dobrowolski and Maciej Ziemba and Rafał Prokopowicz and Tymoteusz Ciuk},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/09/PTP2025_SA.pdf},

year  = {2025},

date = {2025-09-26},

urldate = {2025-09-26},

booktitle = {IX Kongres Polskiego Towarzystwa Próżniowego},

address = {Poznań, 25-26 września},

abstract = {Dążenie do rozwoju reaktorów opartych na fuzji jądrowej wiąże się z koniecznością pogłębienia wiedzy na temat środowisk silnego promieniowania oraz pilnym opracowaniem technologii diagnostycznych odpornych na ekstremalne warunki radiacyjne. W miarę przesuwania granic technologicznych, materiały i układy pomiarowe wystawione są na działanie promieniowania o coraz większym natężeniu, co zbliża konwencjonalne rozwiązania do granic ich wytrzymałości. Wyzwanie to nabiera szczególnego znaczenia w kontekście praktycznej realizacji syntezy jądrowej jako źródła energii, gdzie niezawodne, odporne na promieniowanie czujniki – zwłaszcza magnetyczne – są kluczowe dla bezpiecznej i ciągłej kontroli procesów zachodzących wewnątrz reaktora. Nasze badania koncentrują się na eksploracji potencjału dwuwymiarowych (2D) struktur węglowych jako detektorów pola magnetycznego zdolnych do pracy w ekstremalnych warunkach środowiskowych, charakterystycznych dla przyszłych elektrowni termojądrowych. W tego typu reaktorach elektronika narażona będzie na wysokie temperatury oraz intensywne promieniowanie jonizujące, w tym neutronowe. Przedstawiamy wyniki eksperymentalnych badań dotyczących wpływu napromieniowania neutronowego na właściwości elektryczne układów opartych na grafenie epitaksjalnym. Wykorzystując min. metody próżniowe, wytworzyliśmy grafen quasi-swobodny z interkalacją wodorową na półizolacyjnych podłożach 4H-SiC(0001) i 6H-SiC(0001), pasywowanych warstwą Al2O3. Układy poddane zostały działaniu strumieni neutronów za pomocą badawczego reaktora jądrowego MARIA. Wśród kluczowych pytań pozostaje kwestia granicznej tolerancji na fluencję neutronów w systemach opartych na grafenie oraz to, czy ograniczona wymiarowość struktur 2D rzeczywiście zapewnia przewagę nad klasycznymi materiałami trójwymiarowymi. Szczególnie istotne jest także zrozumienie wpływu oddziaływań pomiędzy warstwami podłoża a warstwą grafenu w heterostrukturach 2D/3D, które mogą istotnie modyfikować — lub nawet ograniczać — korzyści wynikające z zastosowania architektury 2D. Odpowiedzi na te pytania są niezbędne do zaprojektowania nowej generacji elektroniki opartej na grafenie epitaksjalnym — zdolnej do niezawodnej pracy w warunkach intensywnego promieniowania, tam gdzie tradycyjne materiały i technologie mogą okazać się niewystarczające.



Funding from the Ministry of Science and Higher Education (Poland), Project No. 0512/SBAD/2520},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{VdWM2025_JR,

title = {PtSe2: From Layer to Device},

author = {Jan Raczyński and Michał Szczęsny and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/10/WVWMN2025_JR.pdf},

year  = {2025},

date = {2025-09-02},

urldate = {2025-09-02},

booktitle = {Workshop on Van der Waals Materials for Nanoelectronics},

address = {Poznan, September 1-2},

abstract = {The growing interest in 2D materials in recent years has intensified research into understanding their physicochemical properties and related systems. Among the transition metal dichalcogenides

(TMDs) currently under intensive investigation is PtSe2, which exhibits a high theoretical value of charge carrier mobility and semiconducting properties in the single monolayer,

and high surface chemical stability. These features indicate significant potential for applications, including planar architecture devices based on PtSe2 layers. Furthermore, the energy

band gap in the TMD depends on various factors, such as the number of PtSe2 monolayers, strain in the system, structural defects and doping. The ability to band gap engineering,

combined with the formation of effective electrical contacts, calls for a comprehensive analysis of the physicochemical properties of both PtSe2 and metal/PtSe2 systems.

This presentation will discuss in detail the properties of the PtSe2/Al2O3 systems, in terms of the TMD material thickness, determined using nonpolarized and polarized Raman spectroscopy

(RS) measurements. Further discussion will focus on the influence of the deposited metal layer on the physicochemical properties of the metal/PtSe2 system using spectroscopic (RS and

XPS) and microscopic (SEM and AFM) techniques. These measurements will be presented both for the systems after metallic layer deposition and followed by thermal treatment at 500°C for

30 min. The discussion will conclude with the presentation of the 3L PtSe2-based transfer line measurement structure, fabricated using controlled argon plasma etching. The argon plasma

etching method, combined with the RS measurements, allows for the precise analysis of the PtSe2 layer degradation dynamics.



Funding from the National Science Centre (Poland) Project No. 2019/35/O/ST5/01940

Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2520},

note = {Invited lecture},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{PhD_SF2025_WR,

title = {In the heart of the reactor: testing graphene for neutron-resilient electronics},

author = {Wiktoria Reddig and Semir El-Ahmar and Rafał Prokopowicz and Tymoteusz Ciuk},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/07/PhD_SF2025_WR.pdf},

year  = {2025},

date = {2025-06-27},

booktitle = {The PhD Science Forum Innovative thinking. Real data. Future science.},

address = {Poznan, June, 27},

abstract = {As the urgency of climate change accelerates, nuclear fusion emerges as a promising long-term energy solution. Among fusion technologies, magnetic confinement systems like tokamaks rely heavily on accurate magnetic field diagnostics. This work explores the development of Hall effect graphene-based magnetic sensors designed to operate in the extreme conditions found inside fusion reactors.

The research focuses on the performance of graphene-based sensors exposed to high temperatures and neutron radiation—two key stressors in fusion environments. To fabricate the sensors, hydrogenintercalated quasi-free-standing (QFS) graphene was grown on semi-insulating 4H-SiC(0001) and 6HSiC(0001) substrates and then coated with a protective Al2O3 layer. Neutron irradiation experiments were carried out at the MARIA reactor, operated by the Polish National Center for Nuclear Research, while thermal effects were evaluated in a separate study [5]. Measurements using the Hall effect, micro-Raman spectroscopy, and density functional theory indicate that the primary cause of performance degradation after irradiation is the loss of hydrogen from the intercalated

layer. This hydrogen depletion disrupts the unique electronic properties of QFS graphene. However, the research also shows that thermal annealing above 200◦C can partially reverse this damage—likely through hydrogen diffusion at elevated temperatures. The effectiveness of recovery depends on how much hydrogen was lost during irradiation [4]. Understanding these degradation and recovery mechanisms is essential for assessing the long-term viability of graphene-based sensors for magnetic diagnostics in fusion reactors and

other high-radiation environments 



Funding from the Ministry of Science and Higher Education (Poland), Project No. 0512/SPHD/2501},

note = {Poster presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{ENYGF_2025,

title = {The impact of neutron radiation and high temperatures on graphene-based magnetic field sensors},

author = {Wiktoria Reddig and Tymoteusz Ciuk and Rafał Prokopowicz and Semir El-Ahmar},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/07/ENYGF-25-Paper_Reddig_rev2.pdf},

year  = {2025},

date = {2025-06-02},

urldate = {2025-06-02},

booktitle = {European Nuclear Young Generation Forum 2025},

address = {Zagreb, June, 2-6},

abstract = {This paper presents new findings on the electrical characterisation of epitaxial graphene-based radiation-resistant magnetic field sensors following exposure to a neutron fluence of 4.0 × 10^18 n/cm² — twice the highest fluence previously examined. The collected results have been framed in the context of existing research. Additionally, the paper outlines future research directions aimed at further investigating the performance of these sensors under varying radiation conditions and exploring ways to enhance their resilience for practical applications.



Funding from the Ministry of Science and Higher Education (Poland), Project No. 0512/SBAD/2520 and 0512/SPHD/2501},

note = {Oral presentation

},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{WBCGE2025_SA,

title = {Epitaxial graphene technology for the future nuclear industry},

author = {Semir El-Ahmar and Maciej J. Szary and Wiktoria Reddig and Jakub Jagiełło and Rafał Prokopowicz and Maciej Ziemba and Artur Dobrowolski and Tymoteusz Ciuk},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/05/WBCGE2025_SA.pdf},

year  = {2025},

date = {2025-05-16},

urldate = {2025-05-16},

booktitle = {Workshop on Bulk Crystal Growth and Epitaxy (WBCGE)},

address = {Warsaw, May 15-16},

abstract = {In the development of magnetically confined fusion reactor technologies, our understanding of high-energy particle radiation environments is continually advancing. This creates an urgent need for diagnostic technologies that can endure extreme radiation exposure. As these technological boundaries expand, materials face radiation intensities that far exceed those encountered in previous decades, pushing conventional systems to their operational limits. This challenge is especially critical in the pursuit of practical fusion energy, where the creation of robust magnetic sensor technologies capable of continuous and reliable operation under intense neutron flux is essential. Our research explores the potential of using two-dimensional (2D) carbon structures as magnetic field detectors capable of operating in the extreme conditions of future thermonuclear power plants. In such reactors, electronics will be exposed to high temperatures and radiation damage. We demonstrate the experimental study on the impact of neutron radiation and determine its influence on the electrical parameters of epitaxial graphene-based systems. We have conducted preliminary research to investigate the impact of high temperature and neutron radiation. For this purpose, we fabricated a hydrogen-intercalated quasi-free-standing graphene on semi-insulating 4H-SiC(0001) and 6H SiC(0001), passivated with an Al2O3 layer. The systems were exposed to neutron fluxes using the MARIA research nuclear reactor. Key open questions include the ultimate neutron fluence tolerance of graphene-based systems and whether the reduced dimensionality offers a significant advantage over traditional 3D materials. Additionally, it's crucial to consider the impact of substrate interactions in 2D/3D heterostructures, as these can undermine or complicate the benefits of 2D architectures. By addressing these challenges and identifying future directions, we can develop a roadmap for epitaxial graphene-based electronics that can withstand and operate reliably in extreme radiation environments, where conventional materials are likely to fail.  



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2520},

note = {Invited lecture},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{PUT_STEM25_PK,

title = {Study of fabrication of InSb thin films on GaAs substrate in potential application for IoT},

author = {Piotr Kałuziak and Jan Raczyński and Semir El-Ahmar and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2025/02/PUT_STEM2025_PK.pdf},

year  = {2025},

date = {2025-01-10},

urldate = {2025-01-10},

booktitle = {PUT STEM 2025},

address = {Poznan, January 10},

abstract = {Indium antimonide (InSb) has been extensively investigated for many years, renowned for its low energy gap of approximately 0.18 eV at room temperature, along with its outstanding mobility of electric charge carriers, recorded at 77000 cm²/(Vs). The advancement of device fabrication techniques creates new opportunities for thin layers of InSb. Implementing the lithography process followed by metal deposition in vacuum conditions onto the graphene layer enables the creation of complex planar structures with distinctive functionality. A minor adjustment to this structuring method makes it feasible to adapt the technology to thicker layers, such as InSb.

High-quality InSb thin films are produced using the Flash Evaporation Method (FEM) under high vacuum conditions on a gallium arsenide (GaAs) substrate. After a modified structuring approach, Hall and TLM structures were created to assess the galvanometric properties of the InSb-based hybrid structures. Furthermore, a structure was proposed to evaluate the effectiveness of the strip magneto sensor (SMS) in the InSb material. Due to the high mobility of the charge carriers in InSb, it is expected that a notable magnetoresistive effect will be observed in specific geometric configurations, which enhances the potential for developing a magnetoresistive sensor that could be an integral component of the Internet of Things (IoT).



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420 and 0512/SBAD/6217

Funding from the National Centre for Research and Development (Poland), Project “MAGSET” No. LIDER/8/0021/L- 11/19/NCBR/2020},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{Technol2024_PK,

title = {Study of InSb Thin Films obtained by imperfect method for nearly perfect applications},

author = {Piotr Kałuziak and Jan Raczyński and Semir El-Ahmar and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/12/Technolutions2024_PK.pdf},

year  = {2024},

date = {2024-11-26},

booktitle = {Technolutions 2024},

address = {Warsaw, November 26-27},

abstract = {Indium antimonide InSb is a III V group crystalline semiconductor with a room temperature energy gap of 0,18 eV a high electron mobility of 78 000 cm²/Vs hole mobility of 850 cm²/Vs which is crucial for efficient electronic devices This increased mobility leads to faster response times in infrared ( photodetectors, improving sensitivity and operational speed. InSb thin films can be grown on gallium arsenide substrates using Molecular Beam Epitaxy (MBE). MBE enhances film quality through precise deposition control, including environmental regulation, atomic layer deposition, flux monitoring, temperature control and the use of intermediate layers. Lately the MBE method was improved, which his resulted in more homogeneous InSb films In these studies, it was decided to use the less perfect Flash Evaporation Method (FEM). FEM does not fabricate layers of such good quality as MBE, but it is a cheaper and less demanding method, and what is more, the resulting layer imperfections may have potential applications in cybersecurity as physical unclonable functions(PUF). The studies presented here lead to the determination of the measurability and usability of fabrication defects in future plans to use them as cybersecurity elements.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420 and 0512/SBAD/6217

Funding from the National Centre for Research and Development (Poland), Project “MAGSET” No. LIDER/8/0021/L- 11/19/NCBR/2020},

note = {Poster presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{IWSP2024_KK,

title = {The effects of short-term air exposure of monocrystal HfSe2 surface},

author = {Katarzyna Kwiecień and Jan Raczyński and Agnieszka Puchalska and Ewelina Nowak and Edyta Chłopocka and Damian Kot and Mirosław Szybowicz and Leszek Jurczyszyn and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/09/IWSP2024_KK.pdf},

year  = {2024},

date = {2024-09-23},

booktitle = {IWSP},

address = {Niemcza, September 22-26},

abstract = {One of the ways to improve silicon-based electronics is the integration of silicon with a material that possesses properties such as a sizable band gap (Eg) in the range of 1 - 2 eV and high room temperature carrier mobility (RTCM). HfSe2, which belongs to transition metal dichalcogenides (TMDs) group, is a material that meets these requirements. Predicted RTCM of HfSe2 is the highest among TMDs (3500 cm2 V-1 s-1). Its bulk Eg is 1.1 eV and depends on the number of its layers and on the presence of HfO2 in its subsurface, which widens the Eg up to 2 eV. Due to the sensitivity of HfSe2 to oxidation and its technological importance in possible future applications, we investigated this process for exfoliated bulk HfSe2 crystal under ambient conditions. Our scanning electron microscopy studies show early oxidation with a rapid increase in the Se-rich blister coverage. X-ray photoemission data reveals diffusion of O atoms into the bulk and HfO2 formation. Raman spectroscopy results confirm the coexistence of HfSe2 and HfO2 on the surface. Additionally, we confront the experimental findings with the density functional theory predictions.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420 and 0612/SBAD/6215},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{IWSP2024_JR,

title = {Comparison of different metal/PtSe2 systems},

author = {Jan Raczyński and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/09/IWSP2024_JR.pdf},

year  = {2024},

date = {2024-09-23},

urldate = {2024-09-23},

booktitle = {IWSP},

address = {Niemcza, September 22-26},

abstract = {Today, 2D materials also include Transition Metal Dichalcogenides (TMD), which provide a wide range of charge carrier mobility values and bandgap energy, which depend on the thickness. One of the most promising TMD materials for further applications is PtSe2, which exhibits a chemically nonreactive surface, it is crucial to determine the properties of the metal/PtSe2 interfaces. Different metals form morphologically unique structures on the PtSe2 surface, which requires a comprehensive analysis of physicochemical properties including an analysis of the thermal stability of such systems. This presentation will discuss the properties of the metallic layers (eg. Ni, Ti) with various thicknesses embedded on the surface of the bulk PtSe2 crystal. Particular emphasis will be placed on forming intermixed phases at the interface observed in the form of vibration modes in Raman spectroscopy and the chemical shift in XPS measurements. The observed differences between the metal layer and PtSe2 indicate the distinctive properties of such structures, which translate into the operation of planar architecture sensor devices.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2320

Funding from the National Science Centre (Poland), Project No. 2019/35/O/ST5/01940, NAWA grant No.PPN/STA/2021/1/00043},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{IWSP2024_WK,

title = {Comparative investigation of PtSe2-based systems from 1L to bulk},

author = {Wojciech Koczorowski and Jan Raczyński},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/09/IWSP2024_WK.pdf},

year  = {2024},

date = {2024-09-23},

booktitle = {IWSP},

address = {Niemcza, September 22-26},

abstract = {The Transition Metal Dichalcogenides (TMD) class of materials attracts the interest of researchers and technologists because of their intrinsic physical properties, such as the thickness dependence of electronic properties that switch from semiconducting to metallic in the same material and the possibility of bandgap engineering. PtSe2 is a promising material with potential for future applications due to the chemical stability of the surface and the predicted high charge carrier mobility. In the presentation experimental studies of 1, 2, 3, 5, and 10 L of PtSe2 deposited on an Al2O3 substrate will be shown, including a comparison with the bulk properties. The discussion will focus on the properties of commercially available samples and the impact of temperature on the considered systems (in the range of RT to 520K). Finally, the fabrication of elaborate procedures for the PtSe2-based simple electronic devices will be discussed.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420

Funding from the National Science Centre (Poland), Project No. 2019/35/O/ST5/01940},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{PTP2024_WK,

title = {Charakteryzacja wybranych materiałów TMD zawierających Se},

author = {Wojciech Koczorowski and Jan Raczyński and Katarzyna Kwiecień and Ryszard Czajka},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/09/XIIIKTP-WK.pdf},

year  = {2024},

date = {2024-09-20},

urldate = {2024-09-20},

booktitle = {XIII Konferencja Techniki Próżni},

address = {Warsaw, September 19-20},

abstract = {Dichalkogenki metali przejściowych (TMD) to grupa materiałów dwuwymiarowych, które posiadają ciekawe właściwości fizyczne. Wykazują one silną zależność właściwości elektronowych w funkcji ilości ultra-cienkich warstw (od jednej do kilku ML). Pozwala to uzyskać zarówno charakterystykę półprzewodnikową jak i metaliczną dla tego samego materiału. Powoduje to, że materiały TMD podlegają intensywnym badaniom naukowym. W ramach prezentacji pokazane zostaną wyniki prac eksperymentalnych dotyczących PtSe2 oraz HfSe2, które cechują się dużą wartością ruchliwości nośników ładunków elektrycznych. Istotną cechą różnicującą te materiały jest ich aktywność chemiczna, która jest znacznie większa w przypadku HfSe2. W przypadku PtSe2 główny nacisk postawiony zostanie na analizie widm spektroskopii Ramana (RS) umożliwiającej jednoznaczne określenie ilości ML w układzie. Dla powierzchni kryształu HfSe2 omówione zostaną komplementarne wyniki uzyskane za pomocą technik: skaningowej mikroskopii elektronowej (SEM), rentgenowskiej spektrometrii fotoelektronów (XPS) i RS prezentujące zmiany morfologii warstw przypowierzchniowych, które są efektem ekspozycji na warunki zewnętrzne oraz umożliwiają zrozumienie dynamiki procesu utleniania powierzchni. W końcowej części zaprezentowana zostanie także metoda strukturyzacji prostych urządzeń elektronowych z wykorzystaniem: litografii optycznej, strukturyzowania plazmą argonową oraz osadzania warstw metalicznych z wykorzystaniem osadzania magnetronowego.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420

Funding from the National Science Center (Poland), Project No. 2019/35/O/ST5/01940},

note = {Invited lecture},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{GR2DMAT9_SA,

title = {Exploring the limits of graphene's operation in extreme conditions imposed by the future energy industry},

author = {Semir El-Ahmar and Wiktoria Reddig and Jakub Jagiełło and Maciej J. Szary and Artur Dobrowolski and Rafał Prokopowicz and Maciej Ziemba and Marek Wzorek and Tymoteusz Ciuk},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/09/GR2DMat9_SA.pdf},

year  = {2024},

date = {2024-09-10},

booktitle = {Graphene & 2D Mat. 9},

address = {Poznan, September 8-10},

abstract = {Our research explores the potential of using two-dimensional (2D) carbon structures as magnetic field detectors capable of operating in the extreme conditions of future thermonuclear power plants. In so-called magnetic-confinement fusion reactors, electronics will be exposed to high temperatures and radiation damage. We demonstrate the experimental study on the impact of neutron radiation and determine its influence on the electrical parameters of epitaxial graphene-based systems. We have conducted preliminary research to investigate the impact of high temperature and neutron irradiation separately. For this purpose, we fabricated a hydrogen-intercalated quasi-free-standing (QFS) graphene on semi-insulating 4H-SiC(0001) and 6H-SiC(0001), passivated with an Al2O3 layer [3,4]. The systems were exposed to highenergy neutron fluxes using the MARIA research nuclear reactor. We theorize that the main factor affecting the QFS properties of graphene in tested systems is the depletion of atoms in the hydrogen layer, based on Hall effect measurements and micro-Raman characterization supported by high-resolution transmission electron microscopy. We have predicted, using density functional theory calculations, that damage to the intercalation lowers carrier concentration in graphene. We anticipate that temperatures above 200°C will facilitate the diffusion of the hydrogen atoms from parts with higher to lower concentrations. This effect can reduce the surface area where intercalation is too low to support the separation of the graphene and improve its QFS properties.

Understanding the mechanism of damaging the tested systems by neutron radiation is a key milestone in assessing its suitability for magnetic field detection in harsh environments.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420},

note = {Invited lecture},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{EUROSENSORS_2024_SA,

title = {Hall-effect sensors for extreme temperature applications},

author = {Semir El-Ahmar and Jakub Jankowski and Paweł Czaja and Wiktoria Reddig and Marta Przychodnia and Jan Raczyński and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/09/EuroSensors2024_SA.pdf},

year  = {2024},

date = {2024-09-02},

booktitle = {XXXVI EUROSENSORS conference},

address = {Debrecen, September 1-4},

abstract = {This work is focused on developing magnetic field sensors that rely on the Hall effect and can operate stably in extreme temperatures. We have achieved this by creating a Hall effect structure using indium antimonide and a housing that can withstand an extremely wide range of operating temperatures. Our device has been tested and proven to operate stably at high temperatures up to 350°C, as well as in the cryogenic range using liquid helium. This is a significant milestone as no other magnetic field sensor has been able to perform in such extreme temperature conditions.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420

Funding from the National Centre for Research and Development (Poland), Project “MAGSET” No. LIDER/8/0021/L- 11/19/NCBR/2020},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{EUROSENSORS_2024_WR,

title = {Neutron Radiation Effects on Thin-Film and Two-Dimensional Magnetic Field Sensors},

author = {Wiktoria Reddig and Semir El-Ahmar and Rafał Prokopowicz and Tymoteusz Ciuk},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/09/EuroSensors2024_WR.pdf},

year  = {2024},

date = {2024-09-02},

booktitle = {XXXVI EUROSENSORS conference},

address = {Debrecen, September 1-4},

abstract = {Reporting research findings on two types of magnetic field sensors for use in harsh environments and the impact of high-energy neutron flux on them. Researched sensors being 2-D epitaxially grown quasi- free-standing graphene on SiC and thin film InSb on GaAs. The research constitutes a continuation of the series of studies assessing the radiation resistance of graphene-based sensor platforms compared to classical thin-film magnetic diagnostic systems.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420

Funding from the National Centre for Research and Development (Poland), Project “MAGSET” No. LIDER/8/0021/L- 11/19/NCBR/2020},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{ICEM2024_MN,

title = {SEM observations for biology and medicine without special sample preparation},

author = {Marek Nowicki},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/10/ICEM2024_MN.pdf},

year  = {2024},

date = {2024-07-10},

booktitle = {XVIII International Conference on Electron Microscopy},

address = {Zakopane, June 9-12 },

abstract = {The presentation will show and discuss SEM images of living objects. All observations were made without special sample preparation (e.g. critical point drying, carbon coating). It was crucial to perform measurements in a very short time after placing the objects in a low vacuum.

The following will be presented: an analysis of the structure of eriophyoidea (dimensions) for a better understanding of their biology, an analysis of the central catheters of patients with bacterial and fungal infections, and an analysis of the dissolution of foliar fertilizer used in plant cultivation. 

In each of these cases, a scanning electron microscope operating in a low vacuum was a sufficient tool to obtain valuable results.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2320},

note = {Poster presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{EMSA2024_SA,

title = {Magnetic Diagnostics in Extreme Temperature Conditions},

author = {Semir El-Ahmar and Jakub Jankowski and Paweł Czaja and Wiktoria Reddig and Marta Przychodnia and Jan Raczyński and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/07/EMSA2024_SA.pdf},

year  = {2024},

date = {2024-06-26},

urldate = {2024-06-26},

booktitle = {14th European Magnetic Sensors and Actuators Conference (EMSA)},

address = {Kosice, June 24-27},

abstract = {Magnetic field detection devices are highly valuable in many industries, thanks to the fact that they can measure various quantities such as position, movement, direction, and rotational speed. Nowadays, there is a high demand for electronics that canfunction reliably in harsh environments, including those that can withstand extreme temperatures. Traditional electronics design often requiresactive or passive cooling, but thismay not always be practical or effective. Hence, there is an increasing need for extremeenvironment electronics, particularly in the automotive,space, defense, and energy indus-tries. Our latest reports on semiconductor-based Hall sensors operating in extreme conditions are limited to the temperature range from liquid nitrogen (LN) up to 350C. Research on alternative solutions based on monolayer graphene, in turn, presents tests inthe LN - 500C range in a magnetic field below 1 T. Our research exploresthe potentialof utilizing classic semiconductor thin-film material (donor-doped indium antimonide) asan active layer for a Hall effect sensor that can measure magnetic fields in extreme temperature range from liquid helium (LHe) temperatures up to 350C. We verify the usability, thermal stability of our device, and the linearity of its signal in the magnetic field rangeabove 1T. We also propose a solution to the problem of the sensor package suitable for an extremely wide range of work. We present a full-fledged magnetic field sensor that canmeet industrial requirements, being manufactured using almost exclusively the academic infrastructure of the Poznan University of Technology. Ourfinding is a step forward in thedevelopment of magnetic diagnostic devices capable of operating in a broadly defined extreme environments.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420

Funding from the National Centre for Research and Development (Poland), Project “MAGSET” No. LIDER/8/0021/L- 11/19/NCBR/2020},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{EMSA2024_WR,

title = {Investigating Neutron Radiation Induced Damage on Novel Type of Hall-Effect Sensors},

author = {Wiktoria Reddig and Semir El-Ahmar and Tymoteusz Ciuk and Rafał Prokopowicz},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/07/EMSA2024_WR.pdf},

year  = {2024},

date = {2024-06-25},

urldate = {2024-06-25},

booktitle = {14th European Magnetic Sensors and Actuators Conference (EMSA)},

journal = {European Magnetic Sensors and Actuators Conference (EMSA 2024)},

address = {Kosice, June 24-27},

abstract = {Our research exploresthe potential use of semiconductor thin-film materials andgraphene-based structures for magnetic field detection in harsh environments, par-ticularly in thermonuclear reactors. We have conducted preliminary research to investi-gatetheimpactofhightemperature and neutron irradiation on the electrical prop-erties of these sensors. Our studies involved a 2D material made from hydrogen-intercala-ted quasi-free-standing graphene on semi-insulating 4H-SiC (0001), passivated with anAl2O3layer, and a donor-doped InSb-based thin-film on a semi-insulating GaAs sub-strate. Our research has shown how described systems were affected by fast neutron fluence of 7×10^17cm^(−2) using MARIA research nuclear reactor. Based on Hall effect measurements and micro-Raman analysis, we conjecture that for graphene-based structureater irradiation, the primary factor impacting the electrical characteristics is the depletion of atoms in the hydrogen layer. This phenomenon is expected to decrease the surfacearea of intercalation which becomes too scarce to support graphene separation. However, we observe self-healing abilities at temperatures higher than 200C. To determine if these materials are suitable for magnetic field sensing in thermonuclear reactors, we need to understand how they will be affected by stronger neutron radiation. Therefore, we investigate new modes of damage in 5 times greater neutron fluence (40×10^17cm^(−2)) and how the effects of neutron irradiation differ when the graphene-based sensor’s substrate polytype is changed to 6H-SiC (0001).



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420

Funding from the National Centre for Research and Development (Poland), Project “MAGSET” No. LIDER/8/0021/L- 11/19/NCBR/2020},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{ECOSS37_PK,

title = {Fabrication of Thin-layer InSb-based Planar Devices},

author = {Piotr Kałuziak and Jan Raczyński and Semir El-Ahmar and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/07/ECOSS37_PK.pdf},

year  = {2024},

date = {2024-06-18},

urldate = {2024-06-18},

booktitle = {The European Conference on Surface Science - ECOSS 37 },

address = {Harrogate, June 17-21},

abstract = {For many decades, indium antimonide (InSb) has been a well-studied material that is highly valued for its low energy gap of approximately 0.18 eV at room temperature, as well as its exceptional electric charge carriers mobility value, which stands at 77000 cm2/(V·s). The development of device fabrication technologies opens new possibilities for InSb thin layers. The lithography process application followed by metals deposition under vacuum conditions to the graphene layer makes it possible to fabricate sophisticated planar architectures with unique useability. A slight modification of such structuring procedure allows the transfer of the technology to layers of greater thickness, e.g. InSb. High-quality InSb thin films are fabricated using the flash evaporation technique under HV conditions on a gallium arsenide (GaAs) substrate. Following the modified structurisation procedure the Hall and TLM structures were fabricated to determine the galvanometric properties of the InSb-based hybrid systems. In addition, the structure to test the efficacy of the strip magneto sensor (SMS) in the InSb was proposed. As a result of the high charge carrier mobility of InSb, it is predicted to obtain a significant magnetoresistive effect in specific geometry configurations.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420 and 0512/SBAD/6217

Funding from the National Centre for Research and Development (Poland), Project “MAGSET” No. LIDER/8/0021/L- 11/19/NCBR/2020},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{ECOSS37_JR,

title = {Thermal evolution of the metal/PtSe2 systems studied by Raman Spectroscopy},

author = {Jan Raczyński and Jakub Nowaczyk and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2024/07/ECOSS37_JR.pdf},

year  = {2024},

date = {2024-06-17},

urldate = {2024-06-17},

booktitle = {The European Conference on Surface Science - ECOSS 37 },

address = {Harrogate, June 17-21},

abstract = {The discovery of graphene and its physical properties started a new era in the investigating of thin layer materials. Today, these materials also include Transition Metal Dichalcogenides(TMD), which provide a wide range of physical properties, such as the values of charge carrier mobility and bandgap energy, which depend on the layer thickness. One of the most promising TMD materials is PtSe2 with predicted high charge carrier mobility at room temperature(RT). In that case, it is crucial to determine the physical properties of the thin layer as an active channel in the planar sensor device. To fully understand of the formed interface metal/PtSe2 interface, it is necessary to perform measurements to give insight in to the active channel and interface physical properties both at RT and during thermal treatment. In that case, one of the most crucial methodologies is Raman spectroscopy allow analyze of the characteristic mods’ position transform it into the change of the doping and stress level in the sample PtSe2. The properties of the active layer of PtSe2, especially the changes in the stress and doping type levels at RT and during elevated temperature(up to 473K) will be discussed in this presentation. Simultaneously emphasis will be placed on the properties of the metal(eg.Ti,Ni,Pt)/PtSe2 interfaces and the impact of the deposited metallic layer and thermal treatment on the PtSe2 bulk transformation. The application of the temperature dependent correlation plots allows the determination of the temperature range work of PtSe2 based system for a potential planar device will be presented and discussed.



Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2420

Funding from the National Science Centre (Poland), Project No. 2019/35/O/ST5/01940, NAWA grant No.PPN/STA/2021/1/00043},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}