Fig. 3

Time dependence of the source-drain conductance under different temperatures. a The photoresponse of the device at different temperatures to 620 nm LED with the different input current. b The response time of the device at 20 K, while the input current of LED is 2000 μA. c The wavelength dependence photoelectrical performance of the device at room temperature with the illumination of 260 nm, 620 nm and 945 nm. The inset shows an enlarged version of the photoresponse to 260 nm LED