Characterizing the Impact of hBN Defect Generation on Graphene Device Performance

Hexagonal Boron Nitride (hBN) has emerged as the favored substrate for graphene devices due to its atomic flatness and cleaner charge environment compared to SiO2. hBN has also attracted significant research attention as a host for defect-based quantum sensors generated via irradiation since its two-dimensional (2D) structure facilitates nanometer-scale standoff distances and integration with 2D devices. Irradiated hBN with built-in quantum sensors can potentially serve as a dual-purpose substrate/encapsulation layer and sensing platform for hBN/graphene heterostructure devices. However, the impact of highly defective hBN on graphene device properties is not well understood and has not been characterized. We investigate graphene Hall devices encapsulated with defective hBN and characterize their performance as a function of hBN defect density. We compare irradiated hBN with pristine hBN, and suggest strategies for mitigating the degradation of graphene device properties by incorporating spacer layers of pristine hBN.