Gate-activated photoresponse in a graphene p-n junction.

Lemme, Max C; Koppens, Frank H L; Falk, Abram L; Rudner, Mark S; Park, Hongkun; Levitov, Leonid S; Marcus, Charles M · Nano Lett · 2011

basic_science · Level V

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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.