High-Temperature Ultrasensitive FET-Based CVD Graphene Hall Probes

High-Temperature Ultrasensitive FET-Based CVD Graphene Hall Probes

WoS Article

Hall probes play a critical role in industrial applications such as electrical compasses, current sensors, and motion detectors; however, their performance often deteriorates at high temperatures. This study presents a magnetic-field probe with an ultrahigh sensitivity of 880 Omega/T at 150 degrees C, achieved using a graphene Hall bar integrated into a field-effect transistor (FET) architecture. To attain this exceptional sensitivity at elevated temperatures, careful control of doping, passivation, and manufacturing defects is essential. The doping level is optimized by adjusting the gate voltage to maintain the carrier concentration near the charge neutrality point (CNP). Further improvements in sensor response at high temperatures, as well as nearly a 2-fold increase in sensitivity at room temperature, are realized through polymer passivation of graphene. In contrast, it is demonstrated that patterning graphene into a narrower channel can increase the number of defects, which reduces the Hall probe's sensitivity. These findings demonstrate the potential of CVD graphene as a durable and high-performance material for Hall probes in challenging environments.

Hall probes play a critical role in industrial applications such as electrical compasses, current sensors, and motion detectors; however, their performance often deteriorates at high temperatures. This study presents a magnetic-field probe with an ultrahigh sensitivity of 880 Omega/T at 150 degrees C, achieved using a graphene Hall bar integrated into a field-effect transistor (FET) architecture. To attain this exceptional sensitivity at elevated temperatures, careful control of doping, passivation, and manufacturing defects is essential. The doping level is optimized by adjusting the gate voltage to maintain the carrier concentration near the charge neutrality point (CNP). Further improvements in sensor response at high temperatures, as well as nearly a 2-fold increase in sensitivity at room temperature, are realized through polymer passivation of graphene. In contrast, it is demonstrated that patterning graphene into a narrower channel can increase the number of defects, which reduces the Hall probe's sensitivity. These findings demonstrate the potential of CVD graphene as a durable and high-performance material for Hall probes in challenging environments.

graphene; Hall probe; field-effect transistor; sensitivity; high temperature

graphene; Hall probe; field-effect transistor; sensitivity; high temperature

SUPALOVÁ, L.; BARTOŠÍK, M.; ŠVARC, V.; MACH, J.; PIASTEK, J.; ŠPAČEK, O.; KONEČNÝ, M.; ŠIKOLA, T.

18.06.2025

AMER CHEMICAL SOC

WASHINGTON

2637-6113

ACS Applied Electronic Materials

7

13

United States of America

5889

5897

9

https://pubs.acs.org/doi/10.1021/acsaelm.5c00351