Figure 2.

a) Photocurrent ΔI versus V _s at T = 300 K and V _g = 0 V under light illumination with a focused laser beam of power P, 10² P, 10³ P, and 10⁴ P (P = 0.5 nW, λ = 633 nm). The inset shows the photocurrent map indicating that ΔI arises primarily from the InSe layer between the two graphene electrodes, g₁ and g₂. b) Photoconductivity spectra at T = 300 K and V _s = 2 V with unfocused light and power P ≈ 10 pW. The inset shows a color map of ΔI versus V _g and V _s with a laser at λ = 633 nm. c) Temporal dependence of the photocurrent (V _g = 0 V, V _s = 1 V, and λ = 633 nm). The dashed line shows the modulation of the laser beam at frequency f = 100 Hz.