Remote CF ₄ Plasma Fluorination of Graphene for Low-Damage Spin–Orbit Engineering

C-F functionalization while minimizing vacancy formation. Nonlocal transport measurements show that the nonlocal resistance increases in fluorinated graphene and decays exponentially with channel length, consistent with spin diffusion and yielding a spin relaxation length of ∼0.4 μm. Within the Elliott-Yafet framework, we estimate an effective SOC energy scale of 4-9 meV. These results provide a Raman-validated, tunable process route for enhancing SOC in graphene while suppressing vacancy damage.