Ordered and Oriented Supramolecular n/p-Heterojunction Surface Architectures: Completion of the Primary Color Collection

Abstract

Abstract:In this study, we describe synthesis, characterization, and zipper assembly of yellow p-oligophenyl naphthalenediimide (POP-NDI) donor-acceptor hybrids. Moreover, we disclose, for the first time, results from the functional comparison of zipper and layer-by-layer (LBL) assembly as well as quartz crystal microbalance (QCM), atomic force microscopy (AFM), and molecular modeling data on zipper assembly. Compared to the previously reported blue and red NDIs, yellow NDIs are more π-acidic, easier to reduce, and harder to oxidize. The optoelectronic matching achieved in yellow POP-NDIs is reflected in quantitative and long-lived photoinduced charge separation, comparable to their red and much better than their blue counterparts. The direct comparison of zipper and LBL assemblies reveals that yellow zippers generate more photocurrent than blue zippers as well as LBL photosystems. Continuing linear growth found in QCM measurements demonstrates that photocurrent saturation at the critical assembly thickness occurs because more charges start to recombine before reaching the electrodes and not because of discontinued assembly. The found characteristics, such as significant critical thickness, strong photocurrents, large fill factors, and, according to AFM images, smooth surfaces, are important for optoelectronic performance and support the existence of highly ordered architectures.

Applications and validations of the Minnesota density functionals

“…Both functionals have also been employed to calculate the structures and potential energy surface of coronene dimers [56], which are prototypical models for p-p interactions between graphene sheets but which have been too large for accurate WFT studies. Because of the importance of p-p stacking, Kishore et al [57] used M06-L and M06-2X to calculate the binding energies in a zipper assembly of yellow p-oligophenyl naphthalenediimide (POP-NDI) donor-acceptor hybrids. Lim and Park [58] employed M06-2X, M06-HF, and M06-L to investigate noncovalent sidewall functionalization of carbon nanotubes, and their study shows that aromatic molecules have greater binding strength than saturated nonaromatic molecules due to the pÁÁÁp stacking interactions.…”

Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons

“…With respect to infinite graphene, PAHs show nonzero tunable bandgaps and are thus of use as chromophores in antennae7, 8, 9, 10, 11, 12 or emissive molecular architectures13, 14, 15, 16, 17, 18, 19 and in general in all optoelectronic applications requiring a tunable semiconducting material 6, 20. By exploiting organic synthetic tools,21, 22 one can tune the molecular HOMO–LUMO gap8 by 1) changing the size and edge of the carbon‐based aromatic framework; 2) varying the molecular planarity upon insertion of bulky substituents or bridging chains; 3) changing the aromatic properties of the constituent monomeric units; 4) varying the peripheral functionalization through the insertion of electron‐donating or electron‐ withdrawing substituents; 5) enclosing structural defects; 6) promoting supramolecular interactions between individual molecules governing their organization into a condensed phase, and 7) replacing selected carbon atoms by isostructural and isoelectronic analogues (i.e., doping).…”

A Dynamic View of Proton-Coupled Electron Transfer in Photocatalytic Water Splitting

“…42,43 The family of NDI chromophores has found wide applications in dye-sensitized devices since their optical properties can be easily tuned over a wide light-spectrum. 44 Furthermore, they allow the construction of n/p-supramolecular heterojunctions presenting antiparallel gradients in electron and holes channels to achieve photoinduced long-distance charge separation and reduce charge recombination. [45][46][47][48] Scheme 1.…”