Since graphene has been a popular topic in recent years, we decide to explore its function as a high-efficiency photodetector. As reported, the vertical devices have much stronger ability in photon harvesting than lateral devices, we choose to make vertical devices. What is new in our design is that we use Ag Nanowires network as one electrode. Ag Nanowires not only can be used as one transparent electrode but also can enhance graphene's absorption of light.