Cyano substituted benzotriazole based polymers for use in organic solar cells. Issue 14 (16th March 2017)

• Record Type: Journal Article
• Authors: Casey, Abby; Green, Joshua P.; Shakya Tuladhar, Pabitra; Kirkus, Mindaugas; Han, Yang; Anthopoulos, Thomas D.; Heeney, Martin
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 14(2017)
• Page Start: 6465
• Page End: 6470
• Publication Date: 2017-03-16
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta00835j
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A new synthetic route to the electron accepting di-cyano substituted benzo[ d ][1, 2, 3]triazole (BTz) monomer 2-(2-butyloctyl)-4, 7-di(thiophen-2-yl)-2 H -benzotriazole-5, 6-dicarbonitrile (dTdCNBTz ) is reported. Abstract : A new synthetic route to the electron accepting di-cyano substituted benzo[ d ][1, 2, 3]triazole (BTz) monomer 2-(2-butyloctyl)-4, 7-di(thiophen-2-yl)-2 H -benzotriazole-5, 6-dicarbonitrile (dTdCNBTz ) is reported. The cyano substituents can be easily introduced to the BTz unit in one step via the nucleophilic aromatic substitution of the fluorine substituents of the fluorinated precursor 2-(2-butyloctyl)-4, 7-di(thiophen-2-yl)-2 H -benzotriazole-5, 6-difluoro (dTdFBTz ). Co-polymers were prepared with distannylated benzo[1, 2- b :4, 5- b ′]dithiophene (BDT) monomers containing either 2-ethylhexylthienyl (T-EH) side chains or 2-butyloctylthienyl (T-BO) side chains via Stille coupling to yield the novel medium band gap polymers P1 and P2 respectively. Whilst the organic photovoltaic (OPV) performance of P1 was limited by a lack of solubility, the improved solubility of P2 resulted in promising device efficiencies of up to 6.9% in blends with PC61 BM, with high open circuit voltages of 0.95 V.