1 research outputs found
“Double-Cable” Conjugated Polymers with Linear Backbone toward High Quantum Efficiencies in Single-Component Polymer Solar Cells
A series of “double-cable”
conjugated polymers were
developed for application in efficient single-component polymer solar
cells, in which high quantum efficiencies could be achieved due to
the optimized nanophase separation between donor and acceptor parts.
The new double-cable polymers contain electron-donating poly(benzodithiophene)
(BDT) as linear conjugated backbone for hole transport and pendant
electron-deficient perylene bisimide (PBI) units for electron transport,
connected via a dodecyl linker. Sulfur and fluorine substituents were
introduced to tune the energy levels and crystallinity of the conjugated
polymers. The double-cable polymers adopt a “face-on”
orientation in which the conjugated BDT backbone and the pendant PBI
units have a preferential π–π stacking direction
perpendicular to the substrate, favorable for interchain charge transport
normal to the plane. The linear conjugated backbone acts as a scaffold
for the crystallization of the PBI groups, to provide a double-cable
nanophase separation of donor and acceptor phases. The optimized nanophase
separation enables efficient exciton dissociation as well as charge
transport as evidenced from the highup to 80%internal
quantum efficiency for photon-to-electron conversion. In single-component
organic solar cells, the double-cable polymers provide power conversion
efficiency up to 4.18%. This is one of the highest performances in
single-component organic solar cells. The nanophase-separated design
can likely be used to achieve high-performance single-component organic
solar cells