Power-conversion efficiencies (PCEs) higher than 19% have been realized from single-junction organic photovoltaics. [4][5][6][7][8] Moreover, ongoing studies on morphology control, energy loss, photophysical analysis, and photon utilization improve our understanding of the photoelectric conversion processes and motivate the development of OSCs. [9][10][11][12][13][14][15][16][17][18] Fundamental intermolecular interactions are widely known, important, and ubiquitous; however, their complicated impact on organic photovoltaics have not been comprehensively researched.Intermolecular interactions, including those between like and unlike molecules, are prevalent in OSCs. Apart from interactions between different layers, [19] intermolecular interactions play complicated roles in heterojunction active layers, owing to multiple-component mixed systems involving thermodynamics and kinetics procedures. [20] Brédas et al. illustrated the detailed relationship between donor/acceptor (D/A) interactions and polarizability, the charge-transfer state, and charge-separated state in fullerene solar cells, thereby highlighting the significance of interactions from the perspective of theoretical simulations. [21] Hou et al. controlled D/A interactions using halogenated end-caps of acceptors and Research on organic solar cells (OSCs) has progressed through material innovation and device engineering. However, well-known and ubiquitous intermolecular interactions, and particularly their synergistic effects, have received little attention. Herein, the complicated relationship between photovoltaic conversion and multidimensional intermolecular interactions in the active layers is investigated. These interactions are dually regulated by side-chain isomerization and end-cap engineering of the acceptors. The phenylalkyl featured acceptors (LA-series) exhibit stronger crystallinity with preferential face-on interactions relative to the alkylphenyl attached isomers (ITIC-series). In addition, the PM6 and LA-series acceptors exhibit moderate donor/acceptor interactions compared to those of the strongly interacting PM6/ITIC-series pairs, which helps to enhance phase separation and charge transport. Consequently, the output efficiencies of all LA series acceptors are over 14%. Moreover, LA-series acceptors show appropriate compatibility, host/guest interactions, and crystallinity relationships with BTP-eC9, thereby leading to uniform and well-organized "alloy-like" mixed phases. In particular, the highly crystalline LA23 further optimizes multiple interactions and ternary microstructures, which results in a high efficiency of 19.12%. Thus, these results highlight the importance of multidimensional intermolecular interactions in the photovoltaic performance of OSCs.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202208986.

The flexibility and stability of organic solar cells (OSCs) have becoming a hotspot research for their practical applicaitons. Molecular arrangement and network morphology of active layer are important factors affecting...

This work demonstrates a novel photovoltaic application in which graphdiyne (GD) can be employed as a host material in a perovskite active layer for the first time. In the device fabrication, the best molar ratio for active materials is verified as PbI2/MAI/GD being 1:1:0.25, yielding a peak power-conversion efficiency of 21.01%. We find that graphdiyne, as the host material, exerts significant influence on the crystallization, film morphology, and a series of optoelectronic properties of the perovskite active layer. A uniform MAPbI3 film with highly crystalline qualities, large domain sizes, and few grain boundaries was realized with the introduction of graphdiyne. Moreover, the current–voltage hysteresis was negligible, and device stability was significantly improved as well. The results indicate that graphdiyne as the host active material presents great potential for the enhancement of the performance of perovskite solar cells.

Ternary organic solar cells (TOSCs) offer a facile and efficient approach to increase the power conversion efficiencies (PCEs). However, the critical roles that guest components play in complicated ternary systems remain poorly understood. Herein, two acceptors named LA1 and LA9 with differing crystallinity are investigated. The overly crystalline LA9 induces large self-aggregates in PM6:LA9 binary system, resulting in a lower PCE (13.12%) compared to PM6:LA1 device (13.89%). Encouragingly, both acceptors are verified as efficient guest candidates into the host binary PM6:NCBDT-4Cl (PCE = 13.48%) and afford markedly improved PCEs up to 15.39% and 15.75% in LA1 and LA9 ternary devices, respectively. Interestingly, the higher crystallinity LA9 reveals smaller interaction energies with both the host acceptor and donor PM6. Compared to LA1, the appropriate mutual interactions in the LA9 ternary system not only induces the orderly crystallinity of PM6 but also better compatibility with the host acceptor, generating further optimized molecular orientations and ternary morphology. Therefore, enhanced charge transport and minimized recombination loss are detected in LA9 ternary devices, affording the most competitive performance among Y6-sbsent TOSCs. This work suggests that complicated intermolecular interactions should be seriously considered when fabricating state-of-the-art multiple components OSCs.

The anisotropic effects and short-range quantum effects are essential characters in the formation of halogen bonds. Since there are an array of applications of halogen bonds and much difficulty in modeling them in classical force fields, the current research reports solely the polarizable ellipsoidal force field (PEff) for halogen bonds. The anisotropic charge distribution was represented with the combination of a negative charged sphere and a positively charged ellipsoid. The polarization energy was incorporated by the induced dipole model. The resulting force field is "physically motivated," which includes separate, explicit terms to account for the electrostatic, repulsion/dispersion, and polarization interaction. Furthermore, it is largely compatible with existing, standard simulation packages. The fitted parameters are transferable and compatible with the general AMBER force field. This PEff model could correctly reproduces the potential energy surface of halogen bonds at MP2 level. Finally, the prediction of the halogen bond properties of human Cathepsin L (hcatL) has been found to be in excellent qualitative agreement with the cocrystal structures.

Organometallic halide perovskites have drawn substantial interest due to their outstanding performance in solar energy conversion and optoelectronic applications. The presence of ferroelectric domain walls in these materials has shown to have a profound effect on their electronic structure.Here, we use a density-functional-based tight-binding model, coupled to nonequilibrium Green's function method, to investigate the effects of ferroelectric domain walls on electronic transport properties and charge carrier recombination in methylammonium lead−iodide perovskite, MAPbI 3 . With the presence of ferroelectric domain walls, segregation of transport channels for electrons and holes is observed, and the conductance of perovskites is substantially increased due to the reduced band gap. In addition, by taking into account interactions with photons in the vacuum environment, it is found that electron−hole recombination in perovskites with ferroelectric domain walls is drastically suppressed due to the segregation of carrier transport paths, which could enhance photovoltaic performance.

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Thanks to the development of acceptor–donor–acceptor (A–D–A) type electron acceptors, organic solar cells (OSCs) have achieved marvelous progress in recent years. However, a systematic investigation about the structure–efficiency relationship is still highly desired to better understand the working mechanisms inside a bulk heterojunction (BHJ). In this study, new acceptors with the synergistic effect of side chain and unilateral π‐bridge strategy are designed, accounting for lower energy loss, expanded absorption, modulated intermolecular interactions and BHJ morphology. As a consequence, the resultant A–D–π–A acceptor ID‐C6Ph‐ST‐4F based binary solar cell receives an impressive efficiency up to 15.36%, much greater than the A–D–A analog ID‐C6Ph‐4F (10.75%), and ranks the best among all small molecular acceptors with symmetric or asymmetric π‐bridges. The results highlight the promising manipulation of phenylalkyl side chain and unilateral π‐bridge on intermolecular interactions among acceptor molecules and interactions between donor and acceptor (D/A) molecules. Superior interactions among acceptor molecules are an essential precondition to ensure preferable molecular assembly for charge transport, and meanwhile, moderately enhanced D/A interactions are also crucial for proper phase‐separation networks with efficient exciton dissociation and charge generation.