Device Model for Graphene Nanoribbon Phototransistor
  An analytical device model for a graphene nanoribbon phototransistor (GNR-PT) is presented. GNR-PT is based on an array of graphene nanoribbons with the side source and drain contacts, which is sandwiched between the highly conducting substrate and the top gate. Using the developed model, we derive the explicit analytical relationships for the source-drain current as a function of the intensity and frequency of the incident radiation and find the detector responsivity. It is shown that GNR-PTs can be rather effective photodetectors in infrared and terahertz ranges of spectrum. 
Victor Ryzhii, Vladimir Mitin, Maxim Ryzhii, Nadezhda Ryabova, and   Taiichi Otsuji