Persistent and Reversible Electrostatic Control of Doping in Graphene/BN Heterostructures

Heterostructures of graphene and hexagonal boron nitride (BN) are highly tunable platforms that enable the study of novel physical phenomena and technologically promising nanoelectronic devices. Recent opto-electronic and scanning tunneling spectroscopy studies on graphene/BN heterostructures have shown that optical and local electric field excitation can be used to modify the electronic properties of these heterostructures. These previous techniques rely on an exposed or optically accessible graphene surface and thus are incompatible with standard top gating techniques. To address this issue, we have developed a new technique that uses substrate backgating to induce electric fields strong enough to ionize defects in the supporting bulk BN. We have optimized the effectiveness of our technique by studying its response to the applied electric field duration, BN thickness, and temperature over multiple devices. We will discuss the latest experimental progress on the development of our persistent and reversible electrostatic doping technique, and demonstrate its flexibility when used in conjunction with other doping methods.