A series of polyfluorene copolymers composed of 9,9-dioctylfluorene (DOF) and 2,3-diphenylfumaronitrile (DPFN), poly(DOF-co-DPFN)s, have been synthesized through a palladium (0)-catalyzed Suzuki coupling reaction, and their light-emitting properties have been investigated. The synthesized copolymers were soluble in common organic solvents such as chloroform, toluene, etc and formed a uniform thin film after spin coating. As the contents of 2,3-diphenylfumaronitrile in the copolymers increases, the optical band gaps of the copolymers decreased and HOMO energy levels were also slightly lowered. The absorption and PL emission spectra of the copolymers containing DPFN units shifted to longer wavelength region than those of poly(9,9-dioctylfluorene). Light-emitting devices were fabricated using these polymers as the emissive layers in an ITO/PEDOT:PSS/Polymer/Balq/LiF/Al configuration.
Two donor–acceptor (D–A) copolymers, based on the donor unit TIPS substituted benzodithiophene (TIPSBDT) and the acceptor quinoxaline-based units with or without fluorine substitution (PTIPSBDT-DTQX and PTIPSBDT-DFDTQX), were designed and synthesized as a donor material for bulk-heterojunction (BHJ) photovoltaic cells. The introduction of F atoms with high electron affinity to be quinoxailine moieties is effective in further lowering both the HOMO and LUMO energy levels of PTIPSBDT-DFDTQX to attain higher open-circuit voltage (Voc). Single junction photovoltaic cells were fabricated, and the polymers:PC71BM active layer morphology was optimized by adding 1,8-diiodooctane (DIO) as an additive. In a single layer photovoltaic device, they showed power conversion efficiencies (PCEs) of 2–6%. The solution process inverted tandem photovoltaic cells, in which two photovoltaic cells with different absorption characteristics are linked to use a wider range of the solar spectrum, were fabricated with each layer processed from solution with the use of BHJ materials comprising semiconducting polymers and fullerene derivatives. We first report here on the design of PTIPSBDT-DFDTQX equivalent poly(3-hexylthiophene), the current medium band gap polymer of choice, which thus is a viable candidate for use in the highly efficient bottom layer in inverted tandem cells.
Semiconducting copolymers composed of 10-(2'-hexylphenothiazine) (PTZ), 9,9-dioctyl-dithienylfluorene (DTF8), {(2E,2'E)-3,3'-[2,5-bis(octyloxy)-1,4-phenylene]-bis[2-(thiophen-2-yl)acrylonitrile]} (OPTAN), and benzo-[1,2,5]-thiadiazole (BT) units, i.e., poly(PTZ-co-OPTAN-co-BT) and poly(DTF8-co-OPTAN-co-BT), were synthesized through Pd(0)-catalyzed Suzuki coupling with appropriate control of the monomer ratio. The optical band gap energies of the polymers were in the range of 1.95-1.77 eV. The energy levels of the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals of the copolymers were determined via cyclic voltammetry and the optical band gap energies. Photovoltaic devices were fabricated using the polymers as p-type donors and [6,6]-phenyl C61-butyric acid methyl ester (PC60BM) or [6,6]-phenyl C71-butyric acid methyl ester (PC70BM) as electron acceptors.
We have found that 9,9′BF can be used as an electron acceptor for P3HT-based OPVs while similar devices using 4,4′BP do not show any photovoltaic effect. This can be related to the respective aromaticity and antiaromaticity of the reduced forms of 9,9′BF or 4,4′BP. The OPV device fabricated using P3HT and 9,9′BF exhibited a PCE of 2.28% with a Voc of 1.07 V, a Jsc of 5.04 mA cm−2, and a FF of 0.42.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
'%3e%3cg id='b'%3e%3cpath id='a' stroke='%23000' stroke-width='2' d='M-6-25H6m-12 3H6m-12 3H6'/%3e%3cuse xlink:href='%23a' y='44'/%3e%3c/g%3e%3cpath stroke='%23fff' d='M0 17v10'/%3e%3ccircle r='12' fill='%23cd2e3a'/%3e%3cpath fill='%230047a0' d='M0-12A6 6 0 0 0 0 0a6 6 0 0 1 0 12 12 12 0 0 1 0-24z'/%3e%3c/g%3e%3cg transform='rotate(-123.69)'%3e%3cuse xlink:href='%23b'/%3e%3cpath stroke='%23fff' d='M0-23.5v3M0 17v3.5m0 3v3'/%3e%3c/g%3e%3c/svg%3e)