Enhancement of the Photoresponse in the Platinum Silicide Photodetector by a Graphene Layer

The use of two-dimensional materials in the photodetector fabrication has received much attention in recent years. Graphene is a two-dimensional material that has been extensively researched to make photodetectors. The responsivity of graphene photodetectors was limited by the low optical absorption in graphene (~2.3% for single layer graphene). Therefore, graphene along with other materials has been used to fabricate a photodetector with the desired properties. The graphene is used for the improvement of the silicide platinum photodetector. The platinum silicide photodetector with graphene has been experimentally fabricated and characterized, and all steps of the device fabrication and the characterization are completely provided in addition to required equations for device analysis is completely provided. A graphene layer is transferred on the platinum silicide layer, and the graphene layer creates the photoconductor gain in the platinum silicide photodetector. In the proposed device, near-infrared light is detected in the platinum silicide, and by placing a layer of graphene on the platinum silicide, the optical current and responsivity increase compared to the platinum silicide photodetector without graphene. Experimental results show that the optical current, external quantum efficiency, and responsivity increase in the platinum silicide photodetector with graphene. The graphene not only functions as the charge transport channel, but also works as a photoconductor. The optical current and responsivity are increased by the platinum silicide photodetector with graphene. In our photodetector, the highest responsivity is 120 mA/W in the 1310 nm wavelength, and the optical current is 100 nA at the applied voltage of 8 V. Our photodetector has optical current, responsivity, and external quantum efficiency twice as much as platinum silicide photodetector. Experimental results show the good performance of graphene with platinum silicide photodetector.