Figure 2.

Device performance. a) I–V curves in dark and under illumination for the perovskite device. b) Photocurrent as a function of drain voltage for a FASnI₃ device under illumination of light with 685 nm wavelength at different intensities. c) Responsivity versus drain voltage relationship under different intensities of light with 685 nm wavelength. Solid dots are experimental data. d) Responsivity versus light intensity under light illumination at wavelengths of 420, 685, and 850 nm, respectively. Applied voltage is 0.5 V and the dotted lines are fitting curves with a formula of $R\hspace{0.17em}\propto \hspace{0.17em}{E}_{\mathrm{e}}^{\beta -1}$.