Figure 6. Characterization of the graphene/Si Schottky
junctions analyzed by SKPM and CAFM. a) Topographical image of the
graphene/Si surface in SKPM mode. b-c) Mapping the distribution of the
surface potential in the presence (“light”) and absence (“dark”) of
light irradiation, respectively. d) The band change between graphene and
Si is illustrated. e) Topographical image of the graphene/Si surface in
CAFM mode. f-g) Mapping the distribution of the surface current in the
presence (“light”) and absence (“dark”) of light illumination,
respectively. h) The current values correspond to the white dotted lines
in Figures 3f-3g. i-k) Images correspond to current maps collected using
various biases and light states, as indicated on each image. l) TypicalI – V curve obtained by sweeping the bias applied to the
graphene/Si Schottky junctions between –3 and + 4 V in the dark
(Average value measured under the 10 × 10 µm2 area).