4 research outputs found
The effect of halogenation on PBDTT-TQxT based non-fullerene polymer solar cells â Chlorination vs fluorination
A universal route to fabricate n-i-p multi-junction polymer solar cells via solution processing
The interconnection layer (ICL) that connects adjacent subcells electrically and optically in solutionâprocessed multiâjunction polymer solar cells must meet functional requirements in terms of work functions, conductivity, and transparency, but also be compatible with the multiple layer stack in terms of processing and deposition conditions. Using a combination of poly(3,4âethylenedioxythiophene):polystyrene sulfonate, diluted in near azeotropic water/nâpropanol dispersions as hole transport layer, and ZnO nanoparticles, dispersed in isoamyl alcohol as electron transport layer, a novel, versatile ICL has been developed for solutionâprocessed tandem and tripleâjunction solar cells in an nâiâp architecture. The ICL has been incorporated in six different tandem cells and three different tripleâjunction solar cells, employing a range of different polymerâfullerene photoactive layers. The new ICL provided an essentially lossless contact in each case, without the need of adjusting the formulations or deposition conditions. The approach permitted realizing complex devices in good yields, providing a power conversion efficiency up to 10%
High-Permittivity Conjugated Polyelectrolyte Interlayers for High-Performance Bulk Heterojunction Organic Solar Cells
International audienceConjugated polyelectrolyte (CPE) interfacial layers present a powerful way to boost the IâV characteristics of organic photovoltaics. Nevertheless, clear guidelines with respect to the structure of high-performance interlayers are still lacking. In this work, impedance spectroscopy is applied to probe the dielectric permittivity of a series of polythiophene-based CPEs. The presence of ionic pendant groups grants the formation of a capacitive double layer, boosting the charge extraction and device efficiency. A counteracting effect is the diminishing affinity with the underlying photoactive layer. To balance these two effects, we found copolymer structures containing nonionic side chains to be beneficial