Enhanced performance of isotype planar heterojunction photoresponsive organic field-effect transistors by using Ag source-drain electrodes

Abstract

Pentacene/lead phthalocyanine (PbPc)-based isotype and fullerene /PbPc-based anisotype planar heterojunction near-infrared photoresponsive organic field-effect transistors (PhOFETs) were fabricated. We compared the performance of the isotype planar heterojunction PhOFET and the anisotype one, and dominantly investigated the effect of contact on the performance of the isotype planar heterojunction devices. The results showed that the isotype planar heterojunction device exhibits a comparable maximum photoresponsivity of 107 mA/W and a comparable maximum photo/dark current ratio of to the anisotype one ( of 109 mA/W and of ), and exhibits superior air stability to the anisotype one. Moreover, it is surprising to find that Ag source-drain electrodes replacing Au ones yield a performance enhancement in isotype PHJ devices, this is mainly because the use of Ag source-drain electrodes enhances the photo-generated exciton dissociation efficiency at the metal/PbPc interface.