Fig. 4: Photoresponse performance and mechanism analyses of the device at different wavelengths under gate voltage modulation.

a Variation curves of the responsivity of the device at different wavelengths with the drain voltage under the gate voltage of 0V. b Variation curves of the responsivity of the device at different wavelengths with the drain voltage under the gate voltage of 1V. c Variation curves of the responsivity of the device at different wavelengths with the drain voltage under the gate voltage of -1V. d Modulation of the device's responsivity at different wavelengths by different gate voltages at the drain voltage of 5V. e Schematic diagram of the band of the device under positive gate voltages. f Schematic diagram of the band of the device under negative gate voltages