Figure 2.

Photovoltaic Effect. (a) Band diagrams at VGS = 0 V (dashed line) and VGS = −60 V (solid line) were obtained by numerical integration of the photocurrent profiles. $\Delta \varphi$ describes the pinning of the Fermi level. Arrows indicate the flow of electrons and holes. (b) Electrical transport characteristic of a graphene transistor (drain current vs gate bias) at a drain bias of 1 mV. Inset: Scanning electron micrograph of the graphene transistor. (c) Photocurrent line scan profiles under different biases. (a) Reproduced with permission from [44]. Copyright American Physical Society, 2009. (b) and (c) reproduced with permission from [45]. Copyright 2009 American Chemical Society, 2009.