Solar MonoLayer LightEmission FM_KPFM HOPG Polytetrafluoroethylene HighAcpectRatio BTO InLiquid optoelectronics self-assembly Adhesive University_of_Regensburg Polyethylene NiFe HydroGel GalliumPhosphide YttriaStabilizedZirconia MagneticForceMicroscopy ThermalProperties Topography UnivOfMaryland atomic_steps ferromagnetic Sphere Mobile NTU tip_bias_mode StrontiuTitanate non_contact Copolymer Al2O3 LiftHeight STM layers