Ptfe Phase YttriaStabilizedZirconia hetero_structure mfm_amplitude ThermalProperties BiFeO3 Pinpoint PFM fluorocarbon rubber AM-KPFM SolarCell MESA structure Oxide OxideLayer Gold sputter AlkaneFilm Sidewall BiVO4 Phosphide Switching Change Chungnam_National_University WWafer chemical_compound Jason TiO2 TappingMode Device Au111 Polyimide non_contact small_scan PUR