ZAKŁAD FIZYKI POWIERZCHNI i NANOTECHNOLOGII

@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}

}

@conference{ZAKOPANE2023RC,

title = {Processing of PtSe2 ultra-thin layers using Ar plasma for applications in planar devices },

author = {Jan Raczyński and Semir El-Ahmar and Ewelina Nowak and Marek Nowicki and Ryszard Czajka and Mirosław Szybowicz and Wojciech Koczorowski},

url = {https://www.nanosam.pl/stmafm2023/files/abstracts_2023_v16.pdf},

year  = {2023},

date = {2023-12-01},

urldate = {2023-12-01},

booktitle = {XII Workshop on Applications of Scanning Probe Microscopy – STM/AFM 2023},

address = {Zakopane, November 29 - December 3},

abstract = {The systems containing the ultra-thin layers of TMD materials (e.g. PtSe2) exhibit interesting physical properties and can be easily integrated into CMOS technology [1].We propose a procedure for the fabrication of simple electronic devices based on PtSe2 ultra-thin layers using Ar plasma processing on commercially available PtSe2/Al2O3 samples [2]. The report contains a detailed analysis of the influence of the Ar plasma treatment time on a system comprising thin PtSe2 layers with a thickness of 1 to 3 monomolecular layers. The impact of the process on the physical properties of the system is also analyzed using Raman Spectroscopy and Atomic Force Microscopy techniques. The electrical properties of devices based on 3ML PtSe2 are characterized using so called Transfer Line Measurements with electrical contacts consisting of the Ni buffer layer and an Au outer electrode contact (with thicknesses of 20 nm and 40 nm, respectively). The results confirm the effectiveness of the proposed approach in the fabrication of planar nano-electronic devices (1÷3 ML thickness of PtSe2) [3].

Figure 1. Representative AFM images (area of 1.5 × 1.5 μm2) of the samples that present the morphology of the continuous PtSe2 layers with thicknesses: A) 1ML PtSe2, B) 2ML PtSe2, and C) 3ML PtSe2. The z range in all images is 1.75 nm. D) Raman spectra of the samples collected before plasma processing. The intensities are normalized to the maximum value in the individual spectra. The Raman modes corresponding to the PtSe2 layer and the Al2O3 substrate are signed [3].

Acknowledgements:

The authors acknowledge the financial support of the National Science Center, Poland, under Project No. 2019/35/O/ST5/01940 and partially the financial support of the Ministry of Education and Science, Poland under Project No. 0512/SBAD/2320.

[1] J. Raczynski, E. Nowak, M. Nowicki, S.El-Ahmar, M. Szybowicz, W. Koczorowski, Materials Science and Engineering B, 2023, 297, 116728.

[2] S. Joseph, J. Mohan, S. Lakshmy, T. Simil, B. Chakraborty, T. Sabu, N. Kalarikkal, Materials Chemistry and Physics, 2023, 297, 127332.

[3] W. Koczorowski, J. Raczyński, S. El-Ahmar, M. Nowicki, M. Szybowicz, R. Czajka, Materials Science in Semiconductor Processing, 2023, 167, 107814.},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{IEEESENSORS2023WR,

title = {High-Temperature Stability of Sensor Platforms Designed to Detect Magnetic Fields in a Harmful Radiation Environment},

author = {Wiktoria Reddig and Marta Przychodnia and Tymoteusz Ciuk and Semir El-Ahmar},

url = {https://ieeexplore.ieee.org/document/10189897},

year  = {2023},

date = {2023-10-31},

booktitle = {IEEE SENSORS 2023},

address = {Vienna, October 29 - November 2},

abstract = {Modern 2-D 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 necessary condition for the potential neutron-resistant sensor is high-temperature stability. In this letter, we bring together two leading high-temperature sensing platforms: graphene-based and Sn-doped InSb-based. Our study focuses on their thermal stability under identical high-temperature and time conditions. We utilized long-term annealing procedures combined with the simultaneous measurement of the Hall effect to reflect both, the temperature conditions during radiation tests of these platforms performed recently in the MARIA research nuclear reactor, as well as postradiation temperature treatment. We showed that long-term annealing at fixed temperature can affect the graphene-based platform to a greater extent; however, variable temperature tests showed better stability of this system. The InSb-based platform, on the other hand, exhibits much better temperature stability when operating up to 200 °C.



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

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{IEEESENSORS2023SA,

title = {Magnetic Field Sensor Operating From Cryogenics to Elevated Temperatures},

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

url = {https://ieeexplore.ieee.org/document/10180063},

year  = {2023},

date = {2023-10-31},

booktitle = {IEEE SENSORS 2023},

address = {Vienna, October 29 - November 2},

abstract = {Magnetic field sensors, based on the Hall effect, in mass production currently have a standard operating temperature limit of 150 °C. There are sensors designed for specific purposes that can function within a limited range of up to 225 °C or even at the temperature of liquid nitrogen or liquid helium. The technology for the production of magnetic field sensors enabling operation in industrial conditions at temperatures significantly exceeding 225 °C or in the full range of temperatures from cryogenics to elevated temperatures (reaching 350 °C) has not yet been developed. In this letter, we present a reliable and high-quality magnetic field sensor that is capable of functioning under a wide range of temperatures. The sensor was developed using mainly the academic infrastructure of the Poznan University of Technology and can be suitable for industrial use.



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

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{ECOSS2023SA,

title = {Two-dimensional and thin-film active layers for magnetic field detection in extreme temperature range},

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

url = {https://nano.put.poznan.pl/wp-content/uploads/2023/09/abstract_SA.pdf},

year  = {2023},

date = {2023-08-31},

booktitle = {European Conference on Surface Science (ECOSS 36)},

address = {Lodz, August 28 - September 1},

abstract = {Detecting magnetic fields can serve as a means of measuring various quantities like position, movement, direction, and rotational speed. This makes magnetic field detection devices highly useful in many industries. Today, electronics that can function dependably in harsh environments are in high demand, including those that can withstand extreme temperatures. Traditional electronics design often requires active or passive cooling, but this may not always be practical or effective. As a result, there is a growing need for extreme environment electronics, particularly in the automotive, space, defense, and energy industries [1]. Our research explores the potential of utilizing modern two-dimensional material, epitaxial graphene on SiC [2] and classic semiconductor thin-film material (n-InSb) [3] as active layers for sensor structures that can measure magnetic fields from cryogenic temperatures up to 350 °C. Using the developed procedures for temperature testing of the manufactured systems, with simultaneous, cyclical measurement of the Hall effect, we can assess the temperature resistance of the tested systems both

in terms of thermal and long-term stability. The conducted research on the active layer and the structure of the sensor is supplemented with temperature tests of the construction materials of the housing of the future device.



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

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{ECOSS2023TG,

title = {On-surface metalation of salophene molecules with Dy on Au(111) substrate},

author = {Tomasz Grzela and Maciej Bazarnik},

url = {https://nano.put.poznan.pl/wp-content/uploads/2023/09/abstract_TG.pdf},

year  = {2023},

date = {2023-08-30},

booktitle = {European Conference on Surface Science (ECOSS 36)},

address = {Lodz, August 28 - September 1},

abstract = {In recent years, metal-organic complexes have garnered much interest as an active area of research as a result of their enormous potential application in, e.g.: high-efficiency organic light-emitting devices, solar cells, photodetectors, or in electrocatalysis [1,2]. Metal-organic complexes are also a promising pathway for microelectronic miniaturization and open up new possibilities in the development of spintronics [3-5]. Since not all complexes are stable in air, in situ on-surface metalation is an attractive alternative to wet chemistry. On-surface metalation of 5,5′-dibromosalophene with 3d transition metals (Co, Fe and Cr) on Cointercalated graphene grown on Ir (111) was shown to be a promising pathway to vary magnetic and electronic properties of metal−organic complexes [6]. Moreover, on-surface metalation gives clean samples of various different metal−organic complexes, without any pollution or contaminations. Within this contribution, we present results focused on in situ under UHV conditions, the on-surface metalation process of 5,5’-dibromosalophene with dysprosium. The metalation is realized in a twostep process deposition of the rare-earth metal atoms on sample kept at room temperature, followed by postprocessing annealing at elevated temperatures. The morphology and electronic structure of the obtained salophene complexes were investigated by using a combination of scanning tunneling

microscopy and spectroscop.},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{ECOSS2023WR,

title = {Exploring possible modes of damage caused by neutron radiation in thin-film and two-dimensional Hall-effect systems},

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

url = {https://nano.put.poznan.pl/wp-content/uploads/2023/09/abstract_WR.pdf},

year  = {2023},

date = {2023-08-29},

urldate = {2023-08-29},

booktitle = {European Conference on Surface Science (ECOSS 36)},

address = {Lodz, August 28 - September 1},

abstract = {We describe the potential use of two-dimensional carbon-based structures and semiconductor thinfilm materials in the energy industry as magnetic field detectors capable of operating under extreme conditions. In magnetic-confinement fusion reactors, electronics will be exposed to high temperatures and radiation damage. Our work demonstrates the experimental study on the impact of neutron irradiation and determining its influence on the electrical parameters of semiconductor thinfilm and two-dimensional systems. For this purpose, we fabricated a 2D-material in form of hydrogenintercalated quasi-free-standing graphene on semi-insulating 4H-SiC (0001), passivated with an Al2O3 layer [1]. The other structure was prepared in the form of donor-doped InSb-based thin-film on a semiinsulating GaAs substrate [2]. The tested systems were exposed to fast neutron fluence of 7×1017 cm-2 using the MARIA research nuclear reactor. For graphene-based structure after irradiation, we theorize that the main factor affecting the electrical parameters is the loss of atoms in the hydrogen layer, based on Hall effect measurements and microRaman characterization. We have predicted, with the use of density functional theory calculations, that damage to the intercalation lowers carrier concentration in graphene. We anticipate that temperatures above 200°C will facilitate diffusion of the hydrogen atoms from parts with higher to lower concentration. This effect can reduce the surface area where intercalation is too low to support the separation of the graphene [3]. 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 environment. 



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

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{ECOSS2023MP,

title = {Comprehensive studies of Gd-Pt surface alloys grown on Pt(111)},

author = {Marta Przychodnia and Michał Hermanowicz and Tomasz Grzela and P Gargiani and Roland Wiesendanger and Maciej Bazarnik},

url = {https://nano.put.poznan.pl/wp-content/uploads/2023/09/abstract_MP.pdf},

year  = {2023},

date = {2023-08-29},

booktitle = {European Conference on Surface Science (ECOSS 36)},

address = {Lodz, August 28 - September 1},

abstract = {Intermetallic compounds consisting of rare earth (RE) metals in combination with noble metals (NM)

are a class of materials with specific properties that promise a wide range of potential applications.

Here, the magnetic properties are defined by indirect interactions between RE atoms via the NM

lattice. Limiting the dimensionality of such a system to 2D (so-called surface alloys) changes the nature of indirect coupling, for example, a GdAu2 surface alloy is ferromagnetic while in bulk this alloy is antiferromagnetic [1]. Recently we showed the formation of three different Gd-Pt surface alloys as a function of growth temperature and Gd coverage on Pt(111) substrate [2]. In this presentation, we give a summary of the structural composition and the electronic properties of the surface alloys, disclosed by a combination of scanning tunneling microscopy and spectroscopy (STM/S) and density functional theory (DFT) calculations. Our analysis will focus on the magnetic properties of the investigated systems probed using XMCD method.},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{ECOSS2023JR,

title = {Properties of the metal/PtSe2 thin layer interfaces},

author = {Jan Raczyński and I Costina and D Spirito and Wojciech Koczorowski},

url = {https://nano.put.poznan.pl/wp-content/uploads/2023/09/abstract_JR.pdf},

year  = {2023},

date = {2023-08-28},

booktitle = {European Conference on Surface Science (ECOSS 36)},

address = {Lodz, August 28 - September 1},

abstract = {The discovery of graphene and its physical properties started a new era in the investigation of thin layer materials. Nowadays, these types of materials also include Transition Metal Dichalcogenides (TMD), which provide a wide range of physical properties, such as the values of the charge carrier mobility and bandgap energy, which depend on the layer thickness. One of the most promising TMD materials is PtSe2, which exhibits a chemically non-reactive surface, it is crucial to determine the properties of the interfaces formed at the metal/PtSe2 junction. Different metals will form morphologically different structures on the PtSe2 active surface, which requires a comprehensive analysis of both the morphology and physicochemical properties with analysis of the thermal stability of such systems. For this purpose, several measurement methods will be used, ranging from Atomic Force Microscopy (AFM), to Raman and X-Ray Photoelectron Spectroscopy (RS, XPS). In this presentation, the properties of the metallic layers (eg.Ni,Pd,Ti) with thicknesses between 10-20nm embedded on surface of the bulk crystal PtSe2 will be discussed. Particular emphasis will be placed on mutual interactions in the interfaces obtained in this way, and also include the effect of thermal treatment on the formation of bonds between the layers observed in both the form of vibration modes in RS and the chemical shift in XPS measurements. In each of the systems and temperature discussed, the surface morphology was also analysed using AFM to determine its changes. The observed differences between different types of metals and the PtSe2 layer indicate different properties of such structures, which translate into the operation of sensor devices based on planar architecture. Particularly crucial here is the increase in the surface roughness of the interface, which translates into an improved contact of the interface and the appearance of chemical interactions between PtSe2 and the metallic layer.



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

Funding from the Ministry of Education and Science (Poland), Project No. 0512/SBAD/2220

Funding from the National Agency for Academic Exchange (Poland), Project No. PPN/STA/2021/1/00043},

note = {Oral presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{ECOSS2023KK,

title = {Morphology and electric properties of oxidized HfSe2 surface},

author = {Katarzyna Kwiecień and Jan Raczyński and Ewelina Nowak and Marek Weiss and Mirosław Szybowicz and Wojciech Koczorowski },

url = {https://nano.put.poznan.pl/wp-content/uploads/2023/09/abstract_KK.pdf},

year  = {2023},

date = {2023-08-28},

booktitle = {European Conference on Surface Science (ECOSS 36)},

address = {Lodz, August 28 - September 1},

abstract = {HfSe2 is a layered material belonging to Transition Metal Dichalcogenides (TMDs) with a bandgap equal to 0.9 eV and 1.2 eV for bulk crystal and monolayer respectively [1]. It has one of the highest theoretically predicted carrier mobility µ (3500 cm2/Vs) among TMDs, however the experimentally measured values of µ are three orders of magnitude lower [1–4]. Such discrepancy arises from high contact resistance between HfSe2 and measurement electrode, which ranges from 50 to 100 kΩ · µm-1 [1]. HfSe2 oxidizes under ambient conditions, which can drastically modify the potential barrier of metal/HfSe2 interface, which in turn, can influence their contact resistance. Moreover, the morphology of HfxOy could affect the effectiveness of the metal electrode contact to HfxOy/HfSe2. The first part of this work is focused on the oxidation dynamics of HfSe2 and the impact of oxidation parameters on the morphology of HfyOx which forms on its surface. The time progression of HfxOy growth was obtained in a quasi-controlled environment. The dependence of its morphology (surface roughness, the size of oxide structures) on the growth parameters has also been investigated using SPM and SEM techniques. The second part of this work concentrates on the procedure of fabricating devices with HfSe2 active layer. Preliminary I/V measurements obtained for this type of device proved that the resistance of the HfyOx/HfSe2 structure decreased with increasing its exposure time to the ambient conditions. Additionally, an effective method of preventing the oxidation of HfSe2 has been proposed and evaluated using Raman Spectroscopy.



by the Ministry of Education and Science (Poland) Project No: 0612/SBAD/6215},

note = {Poster presentation},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}