Structure-Dependent Charge Transfer in Molecular Perylene-Based Donor/Acceptor Systems and Role of Side Chains

Abstract

In organic electronics and optoelectronics several crucial physical processes are related to charge transfer (CT) effects. In this work, we investigate mixing behavior and intermolecular coupling of donor and acceptor molecules in thin films prepared by organic molecular beam deposition (OMBD). Diindenoperylene (DIP) and pentacene (PEN) are used as the donor materials, and perylene diimide derivatives PDIR-CN 2 and PDIF-CN 2 as the acceptor materials.. The formation of charge transfer complexes coupled in the electronic excited state vs. noninteracting phase separating components is studied by structural and optical techniques. The CT mechanism and properties are considered in close connection with the thin film microstructure of the D/A blends which can be controlled via a change of the molecule geometry and/or growth temperature. We discuss two key findings for our systems: (1) The CT intensity correlates directly with the possibility of cocrystallization between acceptor and donor. (2) Side chain modification to tune the ground state energy levels has nearly no effect on the energy of the excited state CT, whereas replacement of molecular core modifies the CT energy correspondingly.

Triplet exciton formation for non-radiative voltage loss in high-efficiency nonfullerene organic solar cells

“…This is also supported by a recent experimental study showing different side substituents have nearly no effect on CT state energy landscapes. 57 A possible reason is that CT state is localized mostly on the backbone and oriented parallel to p-p stacking, which is less affected by the polarization or dipole effect from the fluorinated side chains. 57 Another possible reason is that the HOMO energy is typically extracted from pristine polymer donor film.…”

“…57 A possible reason is that CT state is localized mostly on the backbone and oriented parallel to p-p stacking, which is less affected by the polarization or dipole effect from the fluorinated side chains. 57 Another possible reason is that the HOMO energy is typically extracted from pristine polymer donor film. But in the NFA-based blend film, CT state can hybridize with local excited state in NFA, 17,22,38 which can also explain the seemingly pinned CT energy.…”

Benzodithiophene-Fused Cyclopentannulated Aromatics via a Palladium-Catalyzed Cyclopentannulation and Scholl Cyclodehydrogenation Strategy

“…To complete the ring closing of the flanking thiophene rings to generate the benzodithiophene subunit, a Scholl cyclodehydrogenation with FeCl 3 was utilized to give 1 – 3 in yields of 80–90%. This chemistry provides convenient access to expanded rubicene, − indenopyrene, , and indacenoperylene , derivatives.…”

“…An initial version of this work was deposited in ChemRxiv on April 26, 2021. benzodithiophene subunit, a Scholl cyclodehydrogenation with FeCl 3 was utilized to give 1−3 in yields of 80−90%. This chemistry provides convenient access to expanded rubicene, 40−42 indenopyrene, 43,44 and indacenoperylene 45,46 derivatives.…”

Exploring organic semiconductors in solution: The effects of solvation, alkylization, and doping

“…[29] Further complexity is added by doping, which is routinely exploited in organic semiconductors to improve their electronic performance [28,[30][31][32][33][34][35][36]. The interaction with dopant species leads to supramolecular compounds with unique characteristics that are determined by the hybridization between the donor and the acceptor and by the charge transfer between them [33,35,[37][38][39][40][41]. Also in this scenario, ab initio simulations in vacuo have successfully led to the understanding of the basic mechanisms driving the electronic and optical activity of these complexes [13,18,19,39,40,42].…”