Laser Liftoff Enabled Batch Fabrication of Ultrathin Graphene Hall Devices

When optimizing the interface between low-dimensional materials and flexible substrates, the surface properties are essential for preserving their exceptional electronic properties. This study presents an approach to fabricating flexible low-dimensional electronic devices using a laser liftoff process that enables optimal interface quality and batch fabrication. Graphene Hall sensors on 6-μm polyimide substrates were batch-fabricated to demonstrate the utility of this approach. The sensors showed a linear response to magnetic fields up to 25 mT and an average current-normalized sensitivity of 140 V AT^-1, outperforming other flexible graphene Hall devices without gate modulation or encapsulation. Owing to the ultrathin substrate, sensor-bending tests showed stable electrical characteristics under strain. The developments in this study represent a step toward extending the applications of low-dimensional flexible electronics.