A graphene photodetector

A graphene photodetector comprising:

• a first graphene absorption layer (2) connected to a first metal electrode (3) at a first end (2a) of said first graphene layer (2) and to a second electrode (4) at a second end (2b) of the first graphene layer opposite to the first end (2a), said first and second metal electrodes (3, 4) being referred to as source and drain, respectively,
• said first and second metal electrodes (3, 4) defining on said first graphene layer (2) a channel (5) operating as a plasmonic waveguide,
• a gate dielectric layer (6) interposed between the first graphene layer (2) and a second graphene layer (7),
• said gate dielectric layer (6) being placed on the opposite side of the channel (5) with respect to the first graphene layer (2),
• said second graphene layer (7) being used for electrical gating and comprising first and second gate electrodes (8, 9) proximate to the first metal electrode (3) and the second metal electrode (4), respectively,
• said first and second gate electrodes (8, 9) being centered with respect to said channel (5),
• a photonic dielectric waveguide (10) with a planarized cladding (11) disposed underneath the gate dielectric layer (6), with the first and second gate electrodes (8, 9) remaining interposed between the gate dielectric layer (6) and the cladding (11),
• a distance between the first and the second metal electrodes (3, 4), defining the width of the channel cross-section, being comprised between 100 nm and 600 nm,
• a distance between the first and second gate electrodes (8, 9) being at least 60% of the distance between said first and second metal electrodes (3, 4).