Prominent Short-Circuit Currents of Fluorinated Quinoxaline-Based Copolymer Solar Cells with a Power Conversion Efficiency of 8.0%
Journal
Chemistry of Materials
Journal Volume
24
Journal Issue
24
Pages
4766-4772
Date Issued
2012
Author(s)
Chen, Hsieh-Chih
Chen, Ying-Hsiao
Liu, Chi-Chang
Chien, Yun-Chen
Chou, Shang-Wei
Abstract
A tailor-made medium-band gap fluorinated quinoxaline-based conjugated polymer of PBDT-TFQ was designed and synthesized as a donor material for bulk-heterojunction (BHJ) solar cells. This polymer is possessed of an intrachain donor-acceptor architecture and exhibits a broad and strong absorption spectrum across the entire UV-vis region. The introduction of F atoms with high electron affinity to the quinoxaline moiety is effective in further lowering both the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels of PBDT-TFQ to attain higher open-circuit voltage (Voc). With an optimized blend ratio of PBDT-TFQ:PC71BM (1:1, w/w), a high power conversion efficiency (PCE) of 8.0% was obtained, with a Voc of 0.76 V, a short-circuit current density (Jsc) of 18.2 mA cm-2, and a fill factor (FF) of 58.1% under AM 1.5G irradiation. The resulting copolymer reveals an outstanding Jsc value, arising from the higher hole mobility of PBDT-TFQ, together with the better continuous percolation pathways within the polymer blend for efficient exciton dissociation and charge transport. © 2012 American Chemical Society.
SDGs
Other Subjects
Blend ratios; Bulk heterojunction; Donor-acceptors; Exciton dissociation; Fill factor; High power conversion; Highest occupied molecular orbital; Lowest unoccupied molecular orbital; Photovoltaic; Power conversion efficiencies; Quinoxalines; Absorption spectroscopy; Conversion efficiency; Copolymers; Electron energy levels; Heterojunctions; Open circuit voltage; Semiconductor materials; Solar cells; Solvents; Nanostructured materials
Type
journal article