Fig. 2
From: Dynamic Control of High-Range Photoresponsivity in a Graphene Nanoribbon Photodetector
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs11671-020-03352-7/MediaObjects/11671_2020_3352_Fig2_HTML.png)
a Time-dependent photocurrent measurements of the device without the biased of back-gate and source-drain voltage under on-off light (632 nm) modulation at room temperature. The time-dependence photocurrent was measured under laser illumination with a frequency of 40 Hz (b), 400 Hz (c), and 5000 Hz (d). e Schematic diagram of the GNR photodetector. f Energy diagram of the interface between Si and SiO2 upon light illumination. EC, EV, Efs, and EVAC are the conduction band, valence band, Fermi level, and vacuum level, respectively. Ef and Ef’ are the Fermi level before and after the injection of the electron to the GNR channel. Eg’ is the bandgap of GNRs. Two processes are illustrated: (I) electronic transition from the value band to the conduction band under illumination in Si and SiO2; (II) hole transfer from SiO2 to Si and photon excited carriers drifted through the built-in field