Low-bandgap-conjugated copolymers

Realizing the need for further improvements, design guidelines have been proposed for the synthesis of new low-bandgap conjugated copolymers with deeper highest occupied molecular orbital (HOMO) level (to harvest more incident photons), so that both Jsc (short-circuit current density) and Voc (open-circuit voltage) can be maximized [232,272]. This... 

A. D. Printz, S. Savagatrup, D. J. Burke, T. N. Purdy, D. J. Lipomi, Increased Elasticity of a Low-Bandgap Conjugated Copolymer by Random Segmentation for Mechanically Robust Solar Cells. RSC Adv. 2014, 4, 13635. 

New low-bandgap-conjugated copolymers based on indigo and three different chalcogenophenes (thiophene, selenophene, and teUurophene) denoted... 

Zhou W, Jin F, Huang X et al (2012) A low-bandgap conjugated copolymer based on porphyrin and dithienocoronene diimide with strong two-photon absorption. Macromolecules 45(19) 7823-7828... 

Arias-Pardilla J, Walker W, Wudl F, Otero TF (2010) Reduction and oxidation doping kinetics of an electropolymerized donor-acceptor low-bandgap conjugated copolymer. J Phys Chem B 114 (40) 12777-12784... 

Huang X, Shi Q, Chen W-Q et al (2010) Low-bandgap conjugated donor-acceptor copolymers based on porphyrin with strong two-photon absorption. Macromolecules 43(23) 9620-9626... 

Andersson and coworkers have prepared solar cells based on blends of poly(2,7-(9-(2 -ethylhexyl)-9-hexyl-fluorene)-fl/t-5,5-(4, 7 -di-2-thienyl-2, l, 3 -benzothiadiazole) (223) and PCBM [416]. The polymer shows a Amax (545 nm) with a broad optical absorption in the visible spectrum and an efficiency of 2.2% has been measured under simulated solar light. The same group has also reported the synthesis of low bandgap polymers 200 (1 = 1.25 eV) and 224 (1 = 1.46 eV) which have been blended with a soluble pyrazolino[70]fiillerene and PCBM, respectively, to form bulk heterojunction solar cells of PCE of 0.7% [417] and 0.9% [418]. Incorporation of an electron-delident silole moiety in a polyfluorene chain affords an alternating conjugated copolymer (225) with an optical bandgap of 2.08 eV. A solar cell based on a mixture 1 4 of 225 and PCBM exhibits 2.01% of PCE [419]. 

Li Y, Li Z, Wang C, Li H, Lu H, Xu B, Tian W (2010) Novel low-bandgap oligothiophene-based donor-acceptor alternating conjugated copolymers synthesis, properties, and photovoltaic applications. J Polym Sci Part A Polym Chem 48 2765-2776... 

Zhang S, Guo Y, Fan H, Liu Y, Chen H-Y, Yang G, Zhan X, Liu Y, Li Y, Yang Y (2009) Low bandgap pi-conjugated copolymers based on fused thiophenes and benzothiadiazole synthesis and structure-property relationship study. J Polym Sci A Polym Chem 47 5498... 

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