High responsivity of VIS-NIR photodetector based on Ag2S/MEH-PPV heterojunction

Silver sulfide (Ag2S) quantum dots (QDs), as a new non-toxic and environmentally friendly QD material, has been widely applied in photoelectric device. We synthesized Ag2S QDs by simple chemical method, and constructed quantum dot-polymer heterojunction photodetector (PD) by combining with the Poly (MEH-PPV). The addition of Ag2S QDs improves the light absorption capacity of MEH-PPV in the visible to near infrared range. Then the photoelectric characteristics of the heterojunction photodetector were measured. The optical responsivity and specific detectivity of the device at 405,532,808 nm were 27.5 A/W,2.19 x 1010 Jones, 23.8 A/W,1.62 x 1010 Jones, 51.7 A/W,3.23 x 1010 Jones, respectively. This work will improve the capability of vulcanized MEH-PPV for broad spectrum measurement and weak light detection.