Aurelio Mateo-Alonso

Low‐LUMO Pyrene‐Fused Azaacenes

A series of pyrene-fused azaacenes with four and six linearly fused rings that possess LUMO levels between -3.7 and -4.3u2005eV is reported. These LUMO values are remarkably lower than those typically observed for pyrene-fused azaacenes, even for systems with sixteen linearly fused rings, and are comparable to those observed for state-of-the-art n-azaacenes.

Hexaazatrinaphthylenes with Different Twists

A synthetic strategy that allows the induction of twist angles of different sizes in 5,6,11,12,17,18-hexaazatrinaphthylene (HATNA) chromophores is reported. The different twist angles are accompanied by measurable changes in the emission and electrochemical characteristics of HATNA.

Twisted Aromatic Frameworks: Readily Exfoliable and Solution-Processable Two-Dimensional Conjugated Microporous Polymers

Abstract Twisted two‐dimensional aromatic frameworks have been prepared by overcrowding the nodes with bulky and rigid substituents. The highly distorted aromatic framework with alternating out‐of‐plane substituents results in diminished interlayer interactions that favor the exfoliation and dispersion of individual layers in organic media.

Enhancement of the Performance of Perovskite Solar Cells, LEDs, and Optical Amplifiers by Anti‐Solvent Additive Deposition

The efficiency of perovskite optoelectronic devices is increased by a novel method; its suitability for perovskite solar cells, light-emitting diodes, and optical amplifiers is demonstrated. The method is based on the introduction of organic additives during the anti-solvent step in the perovskite thin-film deposition process. Additives passivate grain boundaries reducing non-radiative recombination. The method can be easily extended to other additives.

Monodisperse N-Doped Graphene Nanoribbons Reaching 7.7 Nanometers in Length

Abstract The properties of graphene nanoribbons are highly dependent on structural variables such as width, length, edge structure, and heteroatom doping. Therefore, atomic precision over all these variables is necessary for establishing their fundamental properties and exploring their potential applications. An iterative approach is presented that assembles a small and carefully designed molecular building block into monodisperse N‐doped graphene nanoribbons with different lengths. To showcase this approach, the synthesis and characterisation of a series of nanoribbons constituted of 10, 20 and 30 conjugated linearly‐fused rings (2.9, 5.3, and 7.7u2005nm in length, respectively) is presented.

Twisted hexaazatrianthrylene: synthesis, optoelectronic properties and near-infrared electroluminescent heterojunctions thereof

The synthesis, optoelectronic properties and near-infrared electroluminescent heterojunctions of a twisted and soluble 7,8,15,16,23,24-hexaazatrianthrylene derivative are reported.

Energy Level Alignment at Metal/Solution-Processed Organic Semiconductor Interfaces

Energy barriers between the metal Fermi energy and the molecular levels of organic semiconductor devoted to charge transport play a fundamental role in the performance of organic electronic devices. Typically, techniques such as electron photoemission spectroscopy, Kelvin probe measurements, and in-device hot-electron spectroscopy have been applied to study these interfacial energy barriers. However, so far there has not been any direct method available for the determination of energy barriers at metal interfaces with n-type polymeric semiconductors. This study measures and compares metal/solution-processed electron-transporting polymer interface energy barriers by in-device hot-electron spectroscopy and ultraviolet photoemission spectroscopy. It not only demonstrates in-device hot-electron spectroscopy as a direct and reliable technique for these studies but also brings it closer to technological applications by working ex situ under ambient conditions. Moreover, this study determines that the contamination layer coming from air exposure does not play any significant role on the energy barrier alignment for charge transport. The theoretical model developed for this work confirms all the experimental observations.

Pyrene-fused bisphenazinothiadiazoles with red to NIR electroluminescence

The synthesis and characterisation of two pyrene-fused phenazinothiadiazole derivatives with different substituents is described. Light-emitting diodes incorporating such derivatives display red to near-infrared electroluminescence with emission peaks at wavelengths as long as 721 nm, illustrating that pyrene-fused bisphenazinothiadiazoles can serve as deep red and NIR emitters.

A non-covalent strategy to prepare electron donor–acceptor rotaxanes

A straightforward non-covalent synthetic strategy for producing donor-acceptor rotaxanes is reported. Femtosecond absorption spectroscopy illustrates that the use of this strategy gives rise to supramolecular chromophores with different electron transfer behavior.

Readily Processable Hole‐Transporting Peropyrene Gels

The development of organic electronics requires scalable solution-processing methods that enable the fabrication of electronic devices over large areas at low cost. The preparation of peropyrene gels constituted of 3D networks of entangled 1D ribbon-like fibrils that extend over the μm scale are now reported. OFETs were easily fabricated by depositing the gels in the sol state over bottom-gate bottom-contact transistors and by allowing its gelation thereafter. Electrical characterisation of such field-effect transistors shows a good balance between processability and performance with hole mobilities that are two orders of magnitude higher than those observed in thin films obtained from non-gelating solvents under the same conditions.