▎ 摘　　要

The low intrinsic absorption and the existence of the inherent defects hamper the monoatomic layer graphene from being a high-performance photoelectric material, which leads to the strategy to form heterostructure by combining graphene with semiconductor materials. In this work, a graphene/GaAs heterostructure based photodetector has been designed and fabricated, in which the two-dimensional electron gas arc enhanced to improve the photoresponse ability at the band of sub-millimeter and Terahertz (THz) wave ranging from 20 GHz to 0. 12 THz. Under 25 GHz radiation, the responsivity of photodetector at room temperature (RT) reaches 20. 6 V.W-1, with the response time of 9.8 mu s and the noise equivalent power (NEP) of 3. 2x10(10)W.Hz(-1/2) under a bias of 400 mV. At 0. 12 THz, the responsivity is determined to be 4.6 V.W-1, with the response time of 10 mu s. And a NEP of 1. 4x10(-9) W.Hz(-1/2) can be achieved under the bias of 400 mV. These results exhibit great application potential for the graphene/GaAs heterostructure based THz photodetectors.