Fig. 3
From: Direct Observation of High Photoresponsivity in Pure Graphene Photodetectors
Photocurrent as a function of source-drain voltage. Time-dependent photocurrent measurements of our graphene photodetector with a positive (a) and negative (b) source-drain bias. These results indicate that the photocurrent can be tuned via a bias of source-drain voltage, indicating that a higher photocurrent can be readily obtained by applying a larger positive source-drain voltage