Fig. 5. Schottky junction mode of the heterostructure.

a I_ds − V_ds curves under temperatures from 300 to 400 K. The inset shows the ideality factor as a function of temperature. b Schematic of the photovoltaic mechanism of the Schottky junction for detecting VIS to NIR light. c I_ds − V_ds curves on a logarithmic scale under the dark state and 830 nm laser illumination. d Temporal response of the photocurrent under laser illumination at 830 nm; the power is 15.7 μW. e Rise and fall times of the normalized photocurrent under zero bias measured by an oscilloscope. f I_ph and responsivity as a function of the incident laser power.