Wide Bandwidth Graphene Photodetectors

Letter abstract
Nature Photonics
Published online: 28 March 2010 | doi:10.1038/nphoton.2010.40

Graphene photodetectors for high-speed optical communications
Thomas Mueller1, Fengnian Xia1 & Phaedon Avouris1

IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, USA

Present address: Vienna University of Technology, Institute of Photonics, 1040 Vienna, Austria

Correspondence to: Fengnian Xia1 e-mail: fxia@us.ibm.com

Correspondence to: Phaedon Avouris1 e-mail: avouris@us.ibm.com


Abstract
Although silicon has dominated solid-state electronics for more than four decades, a variety of other materials are used in photonic devices to expand the wavelength range of operation and improve performance. For example, gallium-nitride based materials enable light emission at blue and ultraviolet wavelengths1, and high index contrast silicon-on-insulator facilitates ultradense photonic devices. Here, we report the first use of a photodetector based on graphene, a two-dimensional carbon material, in a 10 Gbit s−1 optical data link. In this interdigitated metal–graphene–metal photodetector, an asymmetric metallization scheme is adopted to break the mirror symmetry of the internal electric-field profile in conventional graphene field-effect transistor channels, allowing for efficient photodetection. A maximum external photoresponsivity of 6.1 mA W−1 is achieved at a wavelength of 1.55 µm. Owing to the unique band structure of graphene and extensive developments in graphene electronics and wafer-scale synthesis, graphene-based integrated electronic–photonic circuits with an operational wavelength range spanning 300 nm to 6 µm (and possibly beyond) can be expected in the future.