Nickel ChemicalCompound SKPM Annealing Oxide KPFM LightEmission LDPE FrictionalForceMicroscopy Silicon Graphite Piranha molecules FrictionForce plastics Tungsten Fujian Perovskite Organic SiWafer domain_switching INSPParis AM-KPFM DLaTGS Conductive AFM Step PinpointPFM BTO heterojunctions UTEM Yeditepe_University Monisha Sic Tape Cancer