Scanning Probe Nanopatterning and Layer-by-Layer Thinning of Black Phosphorus

Nanopatterning and layer-by-layer thinning of black phosphorus is demonstrated with conductive atomic-force-microscope anodic oxidation. The liquid-phase patterning byproduct is readily removed by water rinsing. An alternating-current bias enables direct nanopatterning and thinning on insulating substrates such as SiO2/Si. Field-effect transistors with patterned channels show significant improvements in current modulation by up to a factor of 50.