1443120-32-8Relevant articles and documents
A polymer design strategy toward green solvent processed efficient non-fullerene polymer solar cells
Qin, Yunpeng,Ye, Long,Zhang, Shaoqing,Zhu, Jie,Yang, Bei,Ade, Harald,Hou, Jianhui
, p. 4324 - 4330 (2018)
So far, the most successful and widely used solvents in polymer solar cells (PSCs) are chlorinated solvents like chloroform (CF), 1,2-dichlorobenzene (DCB) and chlorobenzene (CB), which are highly detrimental to human health and the environment. In this work, by the approach of manipulating flexible and conjugated side groups of a widely used polymer donor material (PBDB-T), two new polymers named PBDB-T-BO and PBDB-BzT are designed and synthesized to improve the solubility and fine-tune the aggregation property in tetrahydrofuran (THF), a much more benign solvent. As a result, an outstanding PCE of 12.10% was achieved with the THF-processed PBDB-BzT:IT-M device. The result in this work demonstrates the importance to modulate the aggregation effect of the polymer in solution by inserting conjugated groups and also suggests a feasible method to convert the main processing solvent of a highly efficient non-fullerene (NF)-PSC from CB into THF.
Synthesis and correlation between structure and photovoltaic performance of two-dimensional BDT-TPD polymers
Hong, Nam Jeong,Park, Hanok,Baek, Myoung-Jin,Lee, Soo-Hyoung,Jeong, Jo,Park, Jun Hui,Zong, Kyukwan
, p. 101 - 111 (2016/06/09)
Four BDT-TPD polymers (PA-PD) were synthesized by modifying the alkylthienyl chains on BDT, placing spacer group between BDT and TPD, and installing extended conjugated side chains on the BDT of the polymer to investigate the correlation between structure and photovoltaic performance for these polymers. The molecular weight of PA-PD polymers ranged from the highest (Mn = 80 kDa for PA) to the lowest (Mn = 7.9 kDa for PD), and their decomposition temperatures at 5% weight loss were in the range 401-435 °C. PA, PB, and PC showed similar UV-vis absorption spectra; however, PD showed much broader absorption spectrum in the entire UV-vis region, because of the extended conjugated side chains. The HOMO levels of the polymers were -5.72, -5.63, -5.48, and -5.61 eV for PA, PB, PC, and PD, respectively, indicating very low-lying HOMO energy levels. The bandgaps of these polymers were calculated and found to be in the range 1.85-1.88 eV. The theoretical calculations clearly show that the torsional angles between the alkylthienyl group and BDT unit of the simplified dimer correlated to the π-orbital delocalization, suggesting that the HOMO π-electrons of vertically aligned conjugated side chains do not delocalize well in the polymers such as PA, PB, and PC bearing high torsional angles. The optimized weight ratios of the polymer to PC61BM were determined to be 1:1, 1:1.5, and 1:1 for PA, PC, and PD, respectively, and the average PCEs of the devices were 5.36%, 4.62%, and 2.74% for PA, PC, and PD, respectively, after optimization with 1,8-diiodooctane (DIO). A relatively small amount of DIO as an additive was necessary to reach the optimal PCEs of the devices, and the device incorporating PC needed only 0.5% DIO to obtain the best PCE. The AFM study reveals that the blend films after adding DIO showed much smooth morphologies, and the blend film of PA exhibited more crystalline property, as shown by the XRD analysis.