Graphene has emerged as an appealing material for a variety of optoelectronic applications due to its unique electrical and optical characteristics. In this thesis, we will present recent advances in plasmonic graphene-based photodetectors and graphene-boron nitride (BN) hetero-structures with con?ned optical architectures. However, low optical absorption of a bare graphene layer limits optical responsivity of a photodetector. Hot electron photo-thermoelectric (PTE) effect is a promising detection mechanism in graphene-based photodetectors. Based on this effect, hot carriers’ temperature pro?le and Seebeck coef?cient (S) create a PTE voltage along the graphene channel. Here, we have used plasmonic nano-gratings on top of the electrodes to create both strong ?eld distribution and asymmetric hot carrier spatial pro?le along one side of graphene channel simultaneously. Therefore, instead of limiting the device to work just by localizing heating on a speci?c junction, using this design we can localize incoming radiation to a speci?c location along the channel even with uniform incoming radiation. Here, we also proposed another solution to overcome absorption problem, by using hybrid plasmonic waveguide (HPW) mechanism. Covering the plasmonic layer in waveguide-integrated con?gurations with two high-index-contrast materials will result in a highly con?ned hybrid plasmonic mode between the metal surface and high-index dielectric waveguide. Keywords: The photo-thermoelectric effect, Hot-electron, Hybrid plasmonic waveguide, Graphene-based photodetectors
