Controlling the charge carrier density of black phosphorus in a rapid plasma doping process

We investigated the control of the charge carrier density of black phosphorus (BP) 2D nanosheets in a rapid plasma doping process. The electronic structure of plasma boron-doped BP was investigated using X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. The characteristics of a doped BP device were evaluated by fabricating a field-effect transistor under spatially controlled doping in BP nanosheets. The results confirmed the incorporation of ionized boron through the plasma doping process, resulting in the donation of strongly electron dope (electron mobility: ~275 cm²/V·s) on the boron-doped BP switching device. In particular, the fabricated p–n homojunction of the BP device showed an excellent photodetection behavior. This work provides a rapid and stable plasma doping technique for two-dimensional nanosheets employed in next-generation electronic and optoelectronic devices.