LiF is a transparent polar dielectric with the highest band gap among known insulators. The introduction of a LiF/graphene stacked structure provides two significant advantages: mobility enhancement and the stability of the Fermi-level-modulated (doped) state without transmittance loss. The former arises from the increased screening of charged impurities by the high-dielectric environment of LiF, and the latter is due to the self-passivation effect on electron doping achieved by surface dipole interaction originating from high polarizability of LiF. Unlike unstable doping methods based on molecular adsorption or chemical bonding, the doping induced by a highly polar dielectric interface maintains stability and can be reliable method, which is compatible with the Si process.