title: Novel donor-acceptor polymer containing 4,7-bis(thiophen-2-yl)benzo[c][1,2,5]thiadiazole for polymer solar cells with power conversion efficiency of 6.21%.
abstract: In order to improve the solution processability of 4,7-bis(thiophen-2-yl)benzo[c][1,2,5]thiadiazole (DTBT)-based polymers, novel donor-acceptor polymer PTOBDTDTBT containing DTBT and benzo[1,2-b:4,5-b']dithiophene (BDT) with conjugated side chain is designed and synthesized with narrow band gap 1.67 eV and low lying HOMO energy level -5.4 eV. The blend film of PTOBDTDTBT and PC71 BM exhibits uniform and smooth film with root-mean-square (RMS) surface roughness 1.15 nm because of the excellent solubility of PTOBDTDTBT when six octyloxy side chains are introduced. The hole mobility of the blend film is measured to be 4.4 × 10(-5) cm(2) V(-1) s(-1) by the space-charge-limited current (SCLC) model. The optimized polymer solar cells (PSCs) based on PTOBDTDTBT/PC71 BM exhibits an improved PCE of 6.21% with Voc = 0.80 V, Jsc = 11.94 mA cm(-2) and FF = 65.10%, one of the highest PCE in DTBT containing polymers.
authors.affiliation: CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
authors.forename: Liangliang
authors.initials: L
authors.lastname: Han
authors.forename: Xichang
authors.initials: X
authors.lastname: Bao
authors.forename: Tong
authors.initials: T
authors.lastname: Hu
authors.forename: Zhengkun
authors.initials: Z
authors.lastname: Du
authors.forename: Weichao
authors.initials: W
authors.lastname: Chen
authors.forename: Dangqiang
authors.initials: D
authors.lastname: Zhu
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Mingliang
authors.initials: M
authors.lastname: Sun
authors.forename: Renqiang
authors.initials: R
authors.lastname: Yang
mesh_terms: D011211:Electric Power Supplies; D055664:Electrochemical Techniques; D004735:Energy Transfer; D004867:Equipment Design; D015394:Molecular Structure; D055668:Photochemical Processes; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012993:Solar Energy; D013830:Thiadiazoles / Q000737:chemistry*
chemical_list: D011108:Polymers; D013830:Thiadiazoles
keywords: electrochemistry; high solubility; photophysics; polymer solar cells; tris(octyloxy)benzene