Theoretical Insight into Multiple Charge-Transfer Mechanisms at the P3HT/Nonfullerenes Interface in Organic Solar Cells

Abstract

Poly(3-hexylthiophene) (P3HT)-based organic solar cells (OSCs) have been developed in recent years because of their advantages such as easy production, low cost, and large-area manufacture. However, fewer nonfullerene acceptors with higher power conversion efficiency (PCE) than PC 61 BM have been explored in P3HT-based OSCs. In this contribution, the excited states were in-depth analyzed toward probing the particularities of superior P3HT/nonfullerene systems. Multiple charge-transfer (CT) mechanisms involving intermolecular electric field (IEF), hot CT states, and direct excitation of CT states were found, which suggests that more favorable CT pathways exist at these P3HT/ nonfullerene interfaces. Accordingly, the calculations on CT rates of all of the investigated donor/acceptor interfaces further verified the positive effect of multiple CT pathways. In addition, the interesting hybrid Frenkel-CT states were first found to be relevant with the stronger electrostatic surface potential (ESP) differences on the donor and acceptor for these P3HT/nonfullerene systems, which may provide a strategy for the design of high-efficiency OSCs.

Exploring Charge Dissociation in a Statistical Sample of Active-Layer Models of an Organic Solar Cell

“…Here, the counterpoised-corrected total interaction energies ( E int , which is described in the Supporting Information) between D CV -1 and C 60 were first calculated to characterize the interaction strength between the donor and acceptor, as reported in ref . The excited energies of the Frenkel exciton (FE) state for the donor ( E FED ) and the lowest CT state ( E CT ) with their respective oscillator strength f CT and f FED were calculated as in our previous work to identify their relative positions and photoabsorption strengths. Meanwhile, the energy difference between FE and CT states, namely, the excess energy E FE‑CT , was also estimated for every stacking pattern, aiming at distinguishing which CT mechanism it belongs to.…”

Analysis of Photosynthetic Systems and Their Applications with Mathematical and Computational Models

“…A possible solution to address this issue has been put forward in [179] by providing a thermodynamically-consistent version of the model that explicitly describes parts of the reaction center and employs a Hamiltonian transfer to describe the energy absorption and transmission instead of a decay rate or sink term. Owing to the difficulties to probe molecular self-assembling and packing structures at the atomic level by experimental techniques, theoretical simulations are becoming a useful tool in our better understanding of the structure-property relationship of the electronic processes for organic solar cells [180][181][182][183][184][185]. Recent advances in the theoretical simulations for organic solar cells ranging from the molecular dynamics simulated packing structures to the electronic processes computed by quantum-chemical, in combination with kinetic Monte Carlo, simulations have been reviewed in [180].…”

Boosted Reactivity of Low-Cost Solar Cells over a CuO/Co3O4 Interfacial Structure Integrated with Graphene Oxide

“…The growing environmental and energy issues caused by the overconsumption of fossil energy have received considerable attention over the years, which calls for the fast development of renewable energy technologies. − As the most abundant renewable and clean energy on Earth, solar energy has long been considered as a competitive substitute for fossil energy, which has greatly stimulated the development of solar cells. − Dye-sensitized solar cells (DSSCs), with the merits of high efficiency, simple assembly technology, and low cost, have attracted tremendous interest among various solar cells. , Generally, a typical DSSC consists of three major parts: a TiO 2 photoanode sensitized by the dye molecules, a counter electrode (CE) attached with electrocatalysts, and electrolytes including a I 3 – /I – redox couple. Among them, CE works on transferring the electrons in the external circuit back to the redox system and catalyzing the reduction of the redox electric pair; thus, the highly active CE materials are beneficial to the conversion efficiency. , As a traditional highly active CE material, Pt has been widely applied in the previous studies.…”