Speaker
Description
Our research explores the potential use of semiconductor thin-film materials and graphene-based structures for magnetic field detection in harsh environments, particularly in thermonuclear reactors. We have conducted preliminary research to investigate the impact of high temperature [1] and neutron irradiation [2,3] on the electrical properties of these sensors. Our studies involved a 2D material made from hydrogen-intercalated quasi-free-standing graphene on semi-insulating 4H-SiC (0001), passivated with an Al$_2$O$_3$ layer [4], and a donor-doped InSb-based thin-film on a semi-insulating GaAs substrate [2]. Our research has shown how described systems were affected by fast neutron fluence of $7\times 10^{17}$ cm$^{-2}$ using MARIA research nuclear reactor. Based on Hall effect measurements and micro-Raman analysis, we conjecture that for graphene-based structure after irradiation, the primary factor impacting the electrical characteristics is the depletion of atoms in the hydrogen layer. This phenomenon is expected to decrease the surface area of intercalation which becomes too scarce to support graphene separation. However, we observe self-healing abilities at temperatures higher than 200 $^{\circ}$C [3]. 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 ($40\times 10^{17}$ cm$^{-2}$) and how the effects of neutron irradiation differ when the graphene-based sensor’s substrate polytype is changed to 6H-SiC (0001).
Acknowledgements
The research has received funding from the National Centre for Research and Development under Grant Agreement No. LIDER/8/0021/L-11/19/NCBR/2020 for project MAGSET and partly from the Ministry of Education and Science (Poland) under Project No. 0512/SBAD/2420.
References
[1] W. Reddig, et al., “High-Temperature Stability of Sensor Platforms Designed to Detect Magnetic Fields in a Harmful Radiation Environment,” IEEE Sensors Letters, vol. 7, no. 8, Aug. 2023, doi: 10.1109/LSENS.2023.3297795.
[2] S. El-Ahmar et al., “The Comparison of InSb-Based Thin Films and Graphene on SiC for Magnetic Diagnostics under Extreme Conditions,” Sensors, vol. 22, no. 14, p. 5258, Jul. 2022, doi: 10.3390/s22145258 .
[3] S. El-Ahmar et al., “Graphene on SiC as a promising platform for magnetic field detection under neutron irradiation,” Applied Surface Science, vol. 590, p. 152992, Jul. 2022, doi: 10.1016/j.apsusc.2022.152992.
[4] T. Ciuk et al., “Defect-engineered graphene-on-silicon-carbide platform for magnetic field sensing at greatly elevated temperatures,” Carbon Trends, vol. 13, no. October, p. 100303, Dec. 2023, doi: 10.1016/j.cartre.2023.100303.
