Optics and Photonics Society of Iran

In this paper, a graphene-based plasmonic photodetector with high performance at telecommunication wavelengths has been proposed. The proposed structure consists of SiO₂/Si substrate, metal nano-grating with periodic structure and graphene layer. The optical and electrical behavior of the structure is numerically investigated. Utilizing only one graphene layer, the results show that the absorption of the structure reaches to more than 0.98 due to the plasmonic coupling phenomena between graphene and metal nano-grating. In this structure, a low dark current and a photocurrent of 0.64 mA at -2.1 V bias and at wavelength of 1.55 µm are obtained. Also, the photoresponsivity of 1300 mA/W at an incident optical power of 0.5 mW is achieved.