Title: Efficient solar cells based on a new polymer from fluorinated benzothiadiazole and alkylthienyl substituted thieno[2,3-f]benzofuran
Authors: Cui, Ruili
Zou, Yingping
Xiao, Lu
Hsu, Chain-Shu
Keshtov, Mukhamed L.
Godovsky, Dmitri Yu.
Li, Yongfang
Department of Applied Chemistry
Keywords: Efficient solar cells;Semiconductor;Power conversion efficiency;Thieno[2,3-f]benzofuran;Fluorinated benzothiadiazole;Methanol treatment
Issue Date: 1-May-2015
Abstract: A new conjugated D-A copolymer, TBFBT, containing a fluorinated benzothiazole electron-acceptor unit and an electron-donor segment of alkylthienyl substituted thieno[2,3-f]benzofuran, was synthesized using a Stille coupling reaction. The resulting copolymer was characterized by elemental analysis, GPC, TGA, UV-Vis absorption spectroscopy and cyclic voltammetry measurements. The copolymer was readily dissolved in common organic solvents, exhibited good film forming properties and displayed a broad absorption from 300 nm to 800 nm with a low optical bandgap of 1.56 eV. Cyclic voltammetry measurement gave HOMO and LUMO energy levels of -5.11 eV and -3.49 eV, respectively. Polymer solar cells based on TBFBT: PC61BM (1:1.5, w/w) demonstrated an initial power conversion efficiency (PCE) of 4.1% with a V-OC of 0.72 V and a J(SC) of 11.6 mA cm(-2). PSCs based on TBFBT:PC71BM (1:1.5, w/w, 3 vol% 1,8-diiodooctane as additive) were further optimized by using methanol. The optimized result exhibited a high PCE up to 6.1% with a high J(SC) of 14.4 mA cm(-2) and FF of 0.62, under the illumination of AM1.5G, 100 mWcm(-2). These investigations indicate that the new copolymer TBFBT is a promising donor material for PSCs and methanol treatment is a simple and effective way to improve PCE. (C) 2015 Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.dyepig.2015.01.021
ISSN: 0143-7208
DOI: 10.1016/j.dyepig.2015.01.021
Volume: 116
Begin Page: 139
End Page: 145
Appears in Collections:Articles