▎ 摘　　要

In this work, a graphene photodetector hybrid with lead sulfide quantum dots (PbS QDs) is introduced, aiming to take both the advantages of broad-spectrum absorption of PbS QDs and ultrafast carrier mobility of graphene. Through coating the PbS QDs on the graphene, a hybrid photodetector was successfully fabricated, and the optical response of this device to the photo illumination was observed from 405 to 980 nm. The experimental results show that the photoresponsivity of the hybrid photodetector is 7.7 x 10(2) A center dot W-1, 6.4 x 10(2) A center dot W-1, 5.4 x 10(2) A center dot W-1 and 2 x 10(2) A center dot W-1 under 0.16 mW/cm(2) laser illumination of 405 nm, 515 nm, 650 nm and 980 nm, respectively. The maximum photoresponsivity of this device is 7.7 x 10(2) A center dot W-1 (8.93 x 10(9) Jones). The photoconductive gain is 3 x 10(7). Moreover, the device can maintain steady photoresponse for more than 250 s and 25 on/off switching cycles at least. It is believed that such a device fabricated by controllable graphene film and PbS QDs with long-time photoresponse stability in broadband spectrum will stimulate the development of novel graphene photodetectors.