Spatially resolved photodoped lateral graphene p-n interfaces characterized by quantum hall measurements

Precise doping of two-dimensional (2D) materials becomes essential for advancing beyond-CMOS technologies. We present an optical doping strategy for h-BN/Graphene/h-BN heterostructures that enables spatially controlled, reversible modulation of carrier type and density in graphene. By selectively activating defect states in h-BN using patterned light sources under fixed gate voltages, we fabricate lateral pnp junctions and probe their properties through magneto-transport measurements at cryogenic temperatures. Unconventional quantized resistance values—including <i>h/3e²</i>, <i>h/15e²</i>, and &#8776;<i>h/35e²</i>—emerge under magnetic fields up to 9 T, alongside a distinct insulating state in the pnp configuration. These results, well-explained by the Landauer-Büttiker formalism, reveal a promising method to engineer sharp doping boundaries and effective ON/OFF switching behavior in otherwise gapless graphene. This approach offers a scalable platform for reconfigurable 2D nanoelectronic devices using widely adopted materials like <i>h</i>-BN.