We report on the preparation of the first complete extreme temperature Hall sensor. This means that the extreme-temperature magnetic sensitive semiconductor structure is built-in an extreme-temperature package especially designed for that purpose. The working temperature range of the sensor extends from −270 °C to +300 °C. The extreme-temperature Hall-sensor active element is a heavily n-doped InSb layer epitaxially grown on GaAs. The magnetic sensitivity of the sensor is ca. 100 mV/T and its temperature coefficient is less than 0.04 %/K. This sensor may find applications in the car, aircraft, spacecraft, military and oil and gas industries.

The ability to precisely measure magnetic fields under extreme operating conditions is becoming increasingly important as a result of the advent of modern diagnostics for future magnetic-confinement fusion devices. These conditions are recognized as strong neutron radiation and high temperatures (up to 350 °C). We report on the first experimental comparison of the impact of neutron radiation on graphene and indium antimonide thin films. For this purpose, a 2D-material-based structure was fabricated in the form of hydrogen-intercalated quasi-free-standing graphene on semi-insulating high-purity on-axis 4H-SiC(0001), passivated with an Al₂O₃ layer. InSb-based thin films, donor doped to varying degrees, were deposited on a monocrystalline gallium arsenide or a polycrystalline ceramic substrate. The thin films were covered with a SiO₂ insulating layer. All samples were exposed to a fast-neutron fluence of ≈$7\times {10}^{17}$ cm⁻². The results have shown that the graphene sheet is only moderately affected by neutron radiation compared to the InSb-based structures. The low structural damage allowed the graphene/SiC system to retain its electrical properties and excellent sensitivity to magnetic fields. However, InSb-based structures proved to have significantly more post-irradiation self-healing capabilities when subject to proper temperature treatment. This property has been tested depending on the doping level and type of the substrate.

In this letter, we demonstrate a Hall effect sensor in the technology of amorphous-Al ₂ O ₃ -passivated transfer-free p-type hydrogen-intercalated quasi-free-standing epitaxial Chemical Vapor Deposition graphene on semi-insulating high-purity on-axis 4H-SiC(0001), pre-epitaxially modified with 5-keV hydrogen (H ⁺ ) ions. The sensor operates between 305 K and 770 K, with a current-mode sensitivity of ~75 V/AT and thermal stability below 0.15 %/K (⩽ 0.03 %/K in a narrower range between 305 K and 700 K). It is a promising two-dimensional platform for high-temperature magnetic diagnostics and plasma control systems for modern tokamak fusion reactors.

Modern two-dimensional carbon materials are being increasingly studied as potential magnetic field sensors for use in environments with harmful radiation, such as neutron radiation present in future fusion reactors. Potential radiation resistance is also demonstrated by classical semiconductor thin-film materials, after appropriate doping. A 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 post-radiation 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 $200 {}^{\circ }\mathrm{C}$

We describe a study concerning two irradiation series of InSb thin films in the form of Hall structures, using the natural neutron spectrum of a thermal-type fission reactor. We used mono- and polycrystalline InSb thin films with various levels of donor doping. The range of electron concentration values of the samples (from 1016 to 1018 cm-3) allowed us to study the impact of predominant thermal neutrons on various InSb structures. Pre-irradiation long-term annealing of the samples at high temperatures ensured the thermal stabilization of the electrical parameters and made it possible to assess only defects introduced by neutrons in post-irradiation heat treatments, without the influence of post-evaporation defects. Neutron fluences of 8.7×1017 cm-2 and 1.2×1018 cm-2 were applied sequentially, and the total fluence was above 2×1018 cm-2. Annealing at high temperatures was performed after each irradiation process to estimate the quantity of donors created and to remove defects arising in the InSb structure. The results demonstrate the possibility of application of the InSb thin film in Neutron-Resistant Hall Sensor (NRHS) for modern technological settings: fusion and fission reactors, particle accelerators, cosmic and other scientific research.