Charge separation in an acceptor–donor–acceptor triad material with a lamellar structure

Abstract

Linking covalently flexible polymer segments to a donor-acceptor-donor triad is an efficient way to gain control over the formation of materials with well-defined lamellar mesostructure of interest for organic photovoltaics.

Femtosecond Dynamics of Photoexcited C60 Films

“…Intermolecular delocalization leads to formation of narrow energy bands, which increases the number of available end states and homogeneously broadens transition for charges and excitons . This effect has been observed a number of times in organic semiconductors, − and it should not be confused with inhomogeneous broadening due to disorder . We note that electron delocalization into fullerene aggregates plays an important role in the functioning of organic solar cells, ,, highlighting the importance of evaluating this parameter via the shape of the C 60 anion band.…”

Quantum Dynamics of Electron–Hole Separation in Stacked Perylene Diimide-Based Self-Assembled Nanostructures

“…Since then, various dyad and triad species (DA, 28 DAD, 50,51 ADA 28,48 ) have been explored, which were prepared in liquid crystalline phases or lamellar nanostructures. 28,48,50,51 More recently, various types of junction-functionalized block cooligomers with related constituents were investigated. 52 The latter study highlights geminate recombination as the dominant loss channel.…”

“…The DA block co-oligomer system under study, illustrated in Figure , belongs to a class of covalently bound DA dyad assemblies combining PDI acceptor moieties with various types of donor units. − ,, Architectures that rely on the self-assembly of such co-oligomers are promising since they should permit the controlled formation of e–h pairs followed by efficient carrier transport along 1D or two-dimensional (2D) conductive channels. In practice, though, these approaches have mostly been limited to power conversion efficiencies (PCE) of 1–2%, inferior to conventional bulk heterojunction architectures.…”

“…However, a PCE of 2.7% was achieved by suitably tuning the band gap of the donor and optimizing the molecular packing. Since then, various dyad and triad species (DA, DAD, , ADA , ) have been explored, which were prepared in liquid crystalline phases or lamellar nanostructures. ,,, More recently, various types of junction-functionalized block co-oligomers with related constituents were investigated . The latter study highlights geminate recombination as the dominant loss channel.…”

Synthesis of Molecular Dyads and Triads Based Upon N‐Annulated Perylene Diimide Monomers and Dimers

“…Organic molecular and polymeric dyads and triads are systems where two or more distinct π‐conjugated systems are present in the same material. Such dyads and triads have been explored for many applications ranging from fundamental energy or charge transfer studies, to functional applications like fluorescence sensing, ambipolar organic field‐effect transistors, and single component organic photovoltaics Dyad systems are built having well‐defined electron donor and acceptor components, which have an energetic offset in their frontier molecular orbitals enabling charge transfer, energy transfer, or both hole and electron transport. These systems can be designed either with metal‐ligand complexes, which are especially effective for photocatalytic transformations, or with organic π‐conjugated systems which have found a wide variety of uses in opto‐electronic applications…”