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

Silver sulfide (Ag 2 S) quantum dots (QDs), as a new non-toxic and environmentally friendly QD material, has been widely applied in photoelectric device. We synthesized Ag 2 S QDs by simple chemical method, and constructed quantum dot-polymer heterojunction photodetector (PD) by combining with the Poly (MEH-PPV). The addition of Ag 2 S 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 × 1010 Jones, 23.8 A/W,1.62 × 1010 Jones, 51.7 A/W,3.23 × 1010 Jones, respectively. This work will improve the capability of vulcanized MEH-PPV for broad spectrum measurement and weak light detection. [Display omitted] • Heterojunction devices were prepared by simple chemical method. • The absorption range of hybrid devices is expanded to near infrared. • The optical responsivity of the device at 808 nm reaches 51.7 A/W. [ABSTRACT FROM AUTHOR]