Fig. 3
a Multi-cycle photocurrent responses to pulsed picoseconds UV laser with a wavelength of 375 nm, at V b = 0.0 V. A short time delay is observed between the electric pulses and laser pulses due to parasitic effect in the external circuit made of the power cable and trans-impedance amplifier connected to Oscilloscope for on-screen display. The effective area is 0.25 mm2. b The respond time of Gr/Si photodetectors with different active areas of 0.0225 and 0.25 mm2 at ambient condition. c The specific detectivity D * and ON/OFF ratio of the Gr/Si photodetector (in vacuum) under reverse bias from 0.0 to −1.0 V. d The LDR and IQE behavior of Gr/Si photodetector over the range of incident light spectra (200–1100 nm) at V b = 0.0 V. IQE > 100% is observed at the wavelength region of 200 to 300 nm
