C1s NEXAFS investigations of PC60BM exposed to oxygen: a novel approach for the comparison of com... more C1s NEXAFS investigations of PC60BM exposed to oxygen: a novel approach for the comparison of computed and experimental spectra
The crystallisation tendency of nonfullerene acceptors was finely controlled by extending the fus... more The crystallisation tendency of nonfullerene acceptors was finely controlled by extending the fused end groups and the nanostructure and device performances of polymer solar cells were optimized by such molecular engineering.
Donor polymer PBDB-T and acceptor polymer PF5-Y5 form D–A complexes in solution, as confirmed by ... more Donor polymer PBDB-T and acceptor polymer PF5-Y5 form D–A complexes in solution, as confirmed by combined absorption, excitation, and emission spectroscopy of blend solutions.
Realising bicontinuous interpenetrating network morphologies – with nanoscale phase separation – ... more Realising bicontinuous interpenetrating network morphologies – with nanoscale phase separation – for donor–acceptor material systems processed from environmentally-friendlier ink formulations.
The quinoxaline-based polymer TQ1 (poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thioph... more The quinoxaline-based polymer TQ1 (poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5- diyl]) is a promising candidate as electron donor in organic solar cells. In combination with the electron acceptor [6,6]- phenyl-C71- butyric acid methyl ester (PC70BM), TQ1 has resulted in solar cells with power conversion efficiencies of 7 %. We have studied TQ1 films, with and without PC70BM, spin-casted from different solvents, by fluorescence spectroscopy and UV/VIS absorption spectroscopy. We used chloroform (CF), chlorobenzene (CB), and odichlorobenzene (o-DCB) as solvents for the coating solutions and 1-chloronaphthalene (CN) as solvent additive. CN addition has been shown to enhance photo-conversion efficiency of these solar cells. Phase-separation causes lateral domain formation in the films and the domain size depends on the solvent . These morphological differences coincide with changes in the spectroscopic patterns of the films. From a spectroscopic point of view, TQ1 acts as fluorescent probe and PC70BM as quencher. The degree of fluorescence quenching is coupled to the morphology through the distance between TQ1 and PC70BM. Furthermore, if using a bad solvent for PC70BM, morphological regions rich in the fullerene yield emission characteristic for aggregated PC70BM. Clear differences were found, comparing the TQ1:PC70BM blend films casted from different solvents and at different ratios between the donor and acceptor. The morphology also influences the UV/VIS absorption spectra, yielding further information on the composition. The results show that fluorescence and UV/VIS absorption spectroscopy can be used to detect aggregation in blended films and that these methods extend the morphological information beyond the scale accessible with microscopy.
Solvent vapor annealing on crystalline DIP and amorphous DBP induces morphological changes, which... more Solvent vapor annealing on crystalline DIP and amorphous DBP induces morphological changes, which can improve organic solar cell efficiency.
C1s NEXAFS investigations of PC60BM exposed to oxygen: a novel approach for the comparison of com... more C1s NEXAFS investigations of PC60BM exposed to oxygen: a novel approach for the comparison of computed and experimental spectra
The crystallisation tendency of nonfullerene acceptors was finely controlled by extending the fus... more The crystallisation tendency of nonfullerene acceptors was finely controlled by extending the fused end groups and the nanostructure and device performances of polymer solar cells were optimized by such molecular engineering.
Donor polymer PBDB-T and acceptor polymer PF5-Y5 form D–A complexes in solution, as confirmed by ... more Donor polymer PBDB-T and acceptor polymer PF5-Y5 form D–A complexes in solution, as confirmed by combined absorption, excitation, and emission spectroscopy of blend solutions.
Realising bicontinuous interpenetrating network morphologies – with nanoscale phase separation – ... more Realising bicontinuous interpenetrating network morphologies – with nanoscale phase separation – for donor–acceptor material systems processed from environmentally-friendlier ink formulations.
The quinoxaline-based polymer TQ1 (poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thioph... more The quinoxaline-based polymer TQ1 (poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5- diyl]) is a promising candidate as electron donor in organic solar cells. In combination with the electron acceptor [6,6]- phenyl-C71- butyric acid methyl ester (PC70BM), TQ1 has resulted in solar cells with power conversion efficiencies of 7 %. We have studied TQ1 films, with and without PC70BM, spin-casted from different solvents, by fluorescence spectroscopy and UV/VIS absorption spectroscopy. We used chloroform (CF), chlorobenzene (CB), and odichlorobenzene (o-DCB) as solvents for the coating solutions and 1-chloronaphthalene (CN) as solvent additive. CN addition has been shown to enhance photo-conversion efficiency of these solar cells. Phase-separation causes lateral domain formation in the films and the domain size depends on the solvent . These morphological differences coincide with changes in the spectroscopic patterns of the films. From a spectroscopic point of view, TQ1 acts as fluorescent probe and PC70BM as quencher. The degree of fluorescence quenching is coupled to the morphology through the distance between TQ1 and PC70BM. Furthermore, if using a bad solvent for PC70BM, morphological regions rich in the fullerene yield emission characteristic for aggregated PC70BM. Clear differences were found, comparing the TQ1:PC70BM blend films casted from different solvents and at different ratios between the donor and acceptor. The morphology also influences the UV/VIS absorption spectra, yielding further information on the composition. The results show that fluorescence and UV/VIS absorption spectroscopy can be used to detect aggregation in blended films and that these methods extend the morphological information beyond the scale accessible with microscopy.
Solvent vapor annealing on crystalline DIP and amorphous DBP induces morphological changes, which... more Solvent vapor annealing on crystalline DIP and amorphous DBP induces morphological changes, which can improve organic solar cell efficiency.
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