Quasi-Free-Standing Bilayer Graphene Hall-Effect Sensor

This paper presents recent progress in the development of the new type of Hall-effect sensor with the graphene layer acting as sensing material. Newly developed Hall-effect sensor is made of quasi-free-standing bilayer graphene structure. The graphene structure is placed inside the standard QFN-32 package for integrated circuits and mounted on the miniature printed circuit board with four leads, which allowed obtaining operational magnetic field sensor. Basic functional properties of the developed sensor were investigated as well as time drift and temperature dependence of these parameters. Performed investigation indicates high linearity of the sensor within the tested range of an external magnetic field. The measured current-related sensitivity of the sensor is about 50 V/AT, without any amplification of the output signal from the graphene structure. Also, long-term tests of sensitivity and offset voltage were performed. The results indicate high stability of the investigated parameters within long time. Obtained results are very promising and indicate the possibility of utilization of the developed sensor in measurement application.