n-Type Conjugated Polymer Based on Dicyanodistyrylbenzene and Naphthalene Diimide Units for All-Polymer Solar Cells

摘要

All polymer solar cells (all-PSCs),possessing superior mechanical strength and flexibility,offer the commercialization opportunity of the PSCs for flexible and portable devices.In this work,we designed and synthesized two copolymer acceptors based on dicyanodistyrylbenzene (DCB) and naphthalene diimide (NDI) units.The corresponding copolymer acceptors are denoted as PDCB-NDI812 and PDCB-NDI1014.The medium band gap copolymer PBDB-T was selected as donor material for investigation of the photovoltaic performance.Two all-PSCs devices showed power conversion efficiencies (PCE) of 4.26％ and 3.43％ for PDCB-NDI812 and PDCB-NDI1014,respectively.The improved PCE was ascribed to the higher short-circuit current (Jsc),greater charge carrier mobility and higher exciton dissociation probability of the PBDB-T:PDCB-NDI812 blend film.These results suggest that DCB unit and NDI unit based copolymer acceptors are promising candidates for high performance all-PSCs.