Phase LDPE piezoelectric force microscopy Photovoltaics Foil FrequencyModulation Reduction HfO2 2d_materials PS_PVAC F14H20 HighAcpectRatio CarbonNanotube PetruPoni_Institute SurfaceOxidation CaMnO3 Mapping Blood Indent Nanostructure BiasMode Iron LowDensityPolyethylene ElectroChemical Phthalocyanine ito_film CastIron high_resolution Chungnam_National_University IIT-chennai ConductiveAFM India Techcomp lift_mode Dr.JurekSadowski