Graphene, as a novel 2D material, has attracted great of interest in optoelectronics owing to its high carrier mobility and broadband absorption. However, Graphene photodetector exhibits low photoresponsivity because of its low light absorption. In this work, we designed a graphene/MoSe<sub>2 </sub> heterostructure photodetector, which exhibits photoresponse ranging from visible to near infrared and an ultrahigh photoresponsivity up to 1:3× 10<sup>4</sup>A/W at 550nm. The electron-hole pairs are excited in a few layered MoSe<sub>2 </sub> and separaed by the built-in electric field. Large number of electrons shifted to graphene while holes remain in the MoSe<sub>2 </sub>, which creates a photogating effect. Moreover, the lifetime of electrons can be greatly extended because the trap of holes in MoSe<sub>2 </sub> delays the recombination in the circuit. This photodetector represents powerful performance in the near-infrared wavelength regime and have the potential application in many area.
Liu Beiyun, You Congya, Zhao Chen, Shen Gaoliang, Liu Yawei, Li Yufo, Yan Hui, Zhang Yongzhe. High responsivity and near-infrared photodetector based on graphene/MoSe<sub>2</sub> Heterostructure[J]. Chinese Optics Letters, 2019, 17(2): .
