High performance photodetector based on graphene/MoS2/graphene lateral heterostrurcture with Schottky junctions

Graphene and other two-dimensional (2D) materials have emerged as promising materials for future optoelectric applications. However, low detectivity of two-dimensional materials based photodetector inhibits their application. Here, we report a lateral graphene/MoS2/graphene (GMG) heterostructure photodetector which was synthesized by chemical vapor disposition (CVD). Electrical measurement shows that on/off ratio is up to 106 and two opposing Schottky junctions are connected in a series. Photocurrent mapping indicates that the Schottky junctions formed by graphene and MoS2 are the core part of the device, where photoexcited electron-hole pairs are spontaneously and rapidly separated. The responsivity is more than 2×103mA/W and the maximum specific detectivity is as high as 1013Jones, respectively. This special design for the 2D materials based photodetector with high detectivity gives great potential for future application in nano-optoelectronic devices.