Graphene-Gated hBN Heterostructures for Electrically Tunable Near-Infrared Single-Photon Sources

To enable electrical control of defect-based single-photon sources, we prioritize hBN/graphene van der Waals heterostructures. Graphene serves as an atomically thin, broadband, transparent, low-capacitance gate and contact that provides local Fermi-level control, efficient charge-state stabilization, and electrostatic screening to suppress spectral diffusion, while supporting Stark tuning and potential high-rate modulation with minimal optical loss. Its transparency preserves collection efficiency and NA, and its high mobility/low density of states permit fine Fermi-level pinning. Our workflow of mechanical exfoliation, solvent cleaning, deterministic stacking, and edge-contacted graphene yields heterostructure stacks conducive to photonic integration. We introduce oxygen-related emitters in hBN via O₂ plasma and use AFM to select flat, clean device regions. Compared with characterizing NIR defects alone, the heterostructure route targets deterministic tuning, reduced noise, and potential integration with cavities. In this work we have completed heterostructure fabrication where forthcoming experiments will map gate-dependent photoluminescence, single-photon purity, linewidths, and stability and benchmark charge-state hysteresis and bleaching resilience under bias. This methodology will establish stable, electrically tunable single-photon emission from hBN defects delivering building blocks for quantum communication, networking, and linear-optical computation.