PiezoelectricForceMicroscopy frequency_modulation NUS_Physics Chemical_Vapor_Deposition Film heterojunctions self_assembly Blend PinPointMode SKKU OpticalModulator TungstenThinFilmDeposition Layer sputter Solar MembraneFilter LateralPFM OrganicSemiconductor TCS semifluorinated_alkane P3HT Gallium LiNbO3 Vanadate CuFoil ring shape Modulus ScanningIon-ConductanceMicroscopy Silver 2d_materials SAM phase_change LateralForceMicroscopy HardDiskMedia IISCBangalore