Researchers at the Toyohashi University of Technology, Japan have announced that they are seeking industrial partners for the commercialization of the Hall effect magnetic field sensors developed by them. The new magnetic field sensors have been developed for operation at high temperatures and in harsh radiation conditions.
AlGaN/GaN Hall sensor
Hall effect sensors are ideal for speed detection, current sensing, positioning and proximity switching applications and are prominently used in the electronic industry for banknote authentication and optical memory disks. However the use of III-V compound and silicon-based Hall effect magnetic field sensors pose several challenges in critical applications such as nuclear power stations and outer space. To overcome the challenges of harmful radiation and fluctuating temperatures, the researchers at Toyohashi University fabricated micro-Hall effect magnetic field sensors with 2D electron gas heterostructures, offering high sensitivity and stability at high proton irradiation fluxes and high temperatures.
The fabricated Hall effect sensors are operable in high temperatures of 400°C and radiation environments using GaN/AIGaN heterostructures, which are gallium nitride based with two-dimensional (2D) electron gas. The GaN/AIGaN heterostructures were chosen since the sensors fabricated using InSb and GaAs did not provide the stability provided by the GaN/AIGaN heterostructures and began degrading when subjected to 120°C temperature.
The potential applications of the micro-Hall sensors include space crafts, nuclear power stations, electric cars and imaging of ferromagnetic domains. Added advantage of the developed micro-Hall sensors is the resistance to 1x1013 cm-2 proton dose ensured by their high 2D electron density and electron mobility.