Figure 1: Experimental scheme for BP bandgap tuning.
From: Efficient electrical control of thin-film black phosphorus bandgap
(a) The schematic view of the dual-gate BP thin-film transistor for the realization of bandgap tuning. (b) The 4 nm-thick BP film conductance in linear (left axis) and logarithmic (right axis) scales as a function of the back gate bias (VBG) at zero top gate bias (VTG=0 V). The conductance G12 is measured using a four-probe scheme as shown in a, to eliminate the effects of the contact resistance. Inset: an optical image of a typical dual-gate BP transistor. Scale bar, 10 μm. (c) High-resolution cross-section transmission electron micrograph showing the BP layer, which is about 4 nm thick. The POx layer between the BP layer and Al2O3 is 2–3 nm thick. Scale bar, 8 nm. (d) Energy dispersive X-ray spectra from three selected spots in c.
