HOPG Optoelectonics FM_SKPM vertical_PFM Edwin MfmAmplitude PetruPoni_Institute piezoelectric force microscopy IndiumTinOxide BCZT MonoLayer CVD graphene_hybrid UnivOfMaryland AtomicLayer CopperFoil CalciumHydroxide hetero_structure Indium_tin_oxide ConductiveAFM molecule Pzt contact HexacontaneFilm Resistance PolyvinylAcetate Korea Typhimurium HanyangUniv polymeric_arrays CuSubstrate Au111 Blend 2dMaterials Metal