title: Gate-activated photoresponse in a graphene p-n junction.
abstract: We study photodetection in graphene near a local electrostatic gate, which enables active control of the potential landscape and carrier polarity. We find that a strong photoresponse only appears when and where a p-n junction is formed, allowing on-off control of photodetection. Photocurrents generated near p-n junctions do not require biasing and can be realized using submicrometer gates. Locally modulated photoresponse enables a new range of applications for graphene-based photodetectors including, for example, pixilated infrared imaging with control of response on subwavelength dimensions.
authors: Department of Physics,  Harvard University , Cambridge, Massachusetts 02138, United States.
authors: Max C
authors: MC
authors: Lemme
authors: Frank H L
authors: FH
authors: Koppens
authors: Abram L
authors: AL
authors: Falk
authors: Mark S
authors: MS
authors: Rudner
authors: Hongkun
authors: H
authors: Park
authors: Leonid S
authors: LS
authors: Levitov
authors: Charles M
authors: CM
authors: Marcus