Molecular Materials For Organic Electronics.

Organic materials have proven to be efficient active materials in electronics, being possible alternatives to inorganic semiconductors in electronic devices, such as organic field effects transistors (OFETs) or organic solar cells. The versatility of organic synthesis allows us to endow small molecules or polymers with the desired optoelectronic properties. However, the final efficiency of a given device is not only based on the molecular design but also on the way the molecules assemble. In this sense, non-covalent interactions play a crucial role as they are able to control the supramolecular assembly. Hydrogen-bonding has been proven a promising strategy to improve the film morphology in organic electronic devices with semiconductors able to efficiently transport charges. In this project, two compounds have been studied, based on a straightforward diketopyrrolopyrrole (DPP) with a thiophene-capped as the electroactive component and amide groups serving as the hydrogen-bonding units1. Theamide groups are positioned with two different topologies, C-centered (C-1) or N-centered (N-1) which are five carbons apart from the lactam rings of the DPP. We have compared these materials with the control derivative, 1, whose structure lack amide groups (Figure 1). Finally, the potential of these semicondcutors as active components in organic electronics have been tested in organic field effects transistors (OFETs).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Sonochemical Synthesis of Optically Tuneable Conjugated Polymer Nanoparticles

The development of novel and simple methodologies for the obtaining of semiconductive polymer nanoparticles with fine-tuned optical properties represents nowadays a challenging research area as it involves a simultaneous chemical modification and nanostructuration of the polymer. Here, starting from poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], this objective is achieved with the one-pot synthesis of oligomers with tunable conjugation length and their nanostructuration, employing a miniemulsion method. Ultrasound irradiation of heterogeneous mixtures leads to the formation of hypochlorous acid that disrupts the electronic conjugation through polymer chain cleavage. Moreover, control over the degree of the electronic conjugation of the oligomers, and therefore of the optical properties, is achieved simply by varying the polymer concentration of the initial solution. Finally, the presence of surfactants during the sonication allows for the formation of nanoparticles with progressive spectral shift of the main absorption (from λ = 476 to 306 nm) and emission bands (from λ = 597 to 481 nm). The integration of conducting polymer nanoparticles into polymeric matrices yields self-standing and flexible fluorescent films

Analysis of morphologic effects of polymeric semiconducting materials by Raman spectroscopy.

The organic electronics research field has greatly advanced in the last decades, already rendering materials able to compete with their inorganic counterparts. However, the final blossoming of this field is expected to come with the complete understanding and control of the charge transport parameters in organic materials. In polymeric semiconductors, tuning the film morphology and crystallinity has been found to be crucial for efficient charge transport in devices. In this sense, planar backbones with locked conformations induced by intramolecular interactions are good candidates for high performing polymers. Thus, being able to elucidate both ordered and disordered phases in semiconducting films has been proven to be of great interest. Raman spectroscopy is a rapid, noninvasive technique able to gather information on molecular and supramolecular levels, thus being really useful for this purpose. In this communication, optical spectroscopies and, in particular Raman spectroscopy, are used to analyze the impact of the gradual fluorination on the electronic properties of donor-acceptor polymers, demonstrating that the final performance is highly dependent on the building blocks in with the fluorine atoms are introduced.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Tunable electroactive oligothiophene-naphthalimide semiconductors via end-capped engineering: cumulative effects beyond the linker

Aiming to obtain novel functional semiconducting materials for their use in organic electronics, the combination of strong donor moieties with electron-withdrawing units is one of the most useful strategies to obtain ambipolar semiconductors with tunable properties. Nowadays most of the efforts headed to efficient materials are based on small changes in the alkyl pendant chains or by replacing single atoms. However, a precise design of new functional materials is still challenging. For this reason, in this work we present a new synthetic approach for achieving redox amphoteric organic semiconductors by tuning their opto-electrochemical properties via rational chemical modifications. All these materials present low-lying LUMO levels, lower than −4.00 eV with broad absorption up to 800 nm in the UV-Vis-NIR spectra. In addition, they have been characterized by DFT, absorption and Raman vibrational spectroscopies, while their charge stabilization abilities are studied by means of spectroelectrochemical techniques. The results point out to a quite complex electronic scenario that goes beyond the expected cumulative effects of the independent molecular units constituting the final molecular assembly.Funding for open access charge: Universidad de Málaga / CBU

Plan estratégico 2020-2024: hotel boutique en Miraflores

El presente trabajo de investigación tiene como objetivo desarrollar un plan estratégico para un hotel boutique ubicado en el distrito de Miraflores (Lima, Perú) que brinda alojamiento y otros servicios afines. La sede donde funciona el hotel es la antigua casona donde vivió Ricardo Palma, por lo que el local está inmerso en la cultura histórica del país. Dicha casona ha sido modernizada para brindar bienestar y tranquilidad a los huéspedes

Ladder-type bithiophene imide-based organic semiconductors: understanding charge transport mechanisms in organic field effect transistors

Different charge transport mechanisms at the device interface are found for a series of ladder-type semiconductors with increasing chain length

Combined theoretical and spectroscopic Raman study of 3,4-ethylenedioxy and S,S-dioxide substituted terthiophenes and their parent polymers

Abstract This paper reports on the analysis of the Raman spectra, supported by DFT quantum chemical calculations, of a series of terthiophenes which present the novelty of being selectively functionalized with sulfone groups to increase their photoluminescence properties. The spectra have been carefully assigned on the basis of the theoretical vibrational eigenvectors. They suggest the occurrence of a segmentation of the electronic structure which can become a crucial feature for optimizing linear and non linear optical properties. Sulfonation fixes the two lone electron pairs of the sulfur atom, in particular that involved in the aromatization of the thiophene ring, thus coexisting two different kind of five member (aromatic and non aromatic) units in the same chain. This duality of the structure gives rise to the splitting of the characteristic Raman lines associated to the CaC/C-C stretching modes into components mainly located either on the external rings or on the internal one. The study also focuses on the electrosynthesized polymers obtained upon electropolymerization of the corresponding terthiophenes.

Ley Orgánica del Sistema Nacional de Archivos

Un grupo de profesionales y representantes de las entidades de diferentes ámbitos se dedicaron al estudio y análisis del marco legal con que contaba el Ecuador en el ámbito archivístico e inició un debate sobre la necesidad de contar con un marco legal más acorde a las exigencias científicas, técnicas que han advertido la necesidad de normar la información custodiada en sus archivos, como garantes de la gestión, transparencia y rendición de cuentas. La metodología utilizada, se basó en una detallada y amplia investigación histórica -por cada grupo de trabajo- de la legislación ecuatoriana en los ámbitos de la archivística y el patrimonio; y, en la segunda fase en la redacción de cada capítulo, lo que permitió a su vez un intercambio de ideas y reflexiones al interior de la Comisión, así como una socialización en los diferentes ámbitos de las instituciones a la que representaba cada delegado. La estructura de la propuesta está diseñada en nueve (9) capítulos con algunas secciones por capítulo, con un total de 132 artículos. A más del capítulo de rigor con que debe contar toda ley, como son el objeto, ámbito, definiciones, principios y obligatoriedad, incluye el capítulo segundo con dos secciones sobre patrimonio documental, el tercero dedicado al sistema nacional de archivos con cinco secciones; un cuarto sobre gestión documental y archivística con cuatro secciones; el quinto relativo a la conservación documental; el sexto concerniente al talento humano con tres secciones; el séptimo dedicado al acceso a la información pública y, el octavo a los documentos electrónicos

Comparing the microstructure and photovoltaic performance of 3 perylene imide acceptors with similar energy levels but different packing tendencies

[Abstract] While it is widely recognized that microstructure plays an important role in the performance of organic photovoltaics (OPV), systematic studies are often challenging, as varying the molecular packing through typical chemical means (such as sidechain tuning) often affects the molecular energy levels, thus preventing a clear correlation. In this work we present the synthesis of three perylene imide (PI) based electron acceptors with almost identical energy levels, but distinct packing tendencies. We confirm our initial hypothesis by measuring solution and solid-state absorption, and cyclic voltammetry as well as characterizing the films by grazing incidence wide angle X-ray scattering (GIWAXS). In a second step, we repeat the characterization of the three materials in blends with two polymer donors, namely PCDTBT or PBDBT, whose energy levels are well aligned with those of the PI acceptors, and which, additionally, exhibit different degrees of structural order. We show how the initial strong difference between acceptors is partially blurred in blends, but still critical. Finally, we correlate our structural data with OPV devices made with the corresponding six blends. Our data suggest that a good donor acceptor marriage should ensure good energy alignment but also exhibit complementary crystallization tendencies of the two components.Ministerio de Ciencia e Innovación; CEX2019-000917-SMinisterio de Ciencia e Innovación; PGC2018-095411-B-I00Ministerio de Ciencia e Innovación; PID2019-106268GB-C33MInisterio de Ciencia e Innovación; PID2019-110305GB-I00Universidad Complutense de Madrid; INV.GR.00.1819.10759Universidad Complutense de Madrid; CT20/19-CT21/19/PEJD-2018-POST/IND-8661PAIJunta de Andalucía; UMA18-FEDERJA-08

V-shaped pyranylidene/triphenylamine-based chromophores with enhanced photophysical, electrochemical and nonlinear optical properties

We report the synthesis and comprehensive study of two chromophores based on 4H-pyranylidene moiety as a part of the π-conjugated spacer. Triphenylamine (TPA) acts as donor and tricarbonitrile-based electron-accepting groups complete these V-shaped D–A–D architectures (A, acceptor; D, donor). Their electrochemical, photophysical and nonlinear optical properties are analyzed in detail by using a joint experimental and theoretical approach. The two chromophores exhibit near-infrared fluorescence, large Stokes shift, enhanced emission in tetrahydrofuran/water mixtures and good photostability. Additionally, the dimerization of triphenylamine groups to tetraphenylbenzidine (TPB) takes place upon electrochemical and chemical oxidation showing their peculiar electrochemical behavior and film formation capabilities. Interestingly, high molecular first hyperpolarizabilities and two-photon absorption cross-sections were found, highlighting their potential applications in electro-optical devices. Overall, our work demonstrates that these near-infrared (NIR) fluorescent chromophores are versatile materials with a myriad of applications ranging from optoelectronics to biological applications.The work at the University of Málaga was funded by the MICINN (PID2019-110305GB-I00, PID2019-104293GB-I00, RTI2018-095410-B-I00, EuroNanoMed 2019 PCI2019-111825-2), the Institute of Health Carlos III (ISCIII) RETIC ARADYAL (RD16/0006/0012) and by the Junta de Andalucıa (P09-FQM-4708, UMA18-FEDERJA-080, UMA18-FEDERJA-007, PIER-0084-2019). The work at the University of Zaragoza was funded by the MICINN (PID2019-104307GB-I00/AEI/10.13039/501100011033) and Gobierno de Aragón (E47_20R). The work at the University of Stuttgart was funded by the German Science Foundation (DFG) through the project “LU 1445/7-1, project number 416982273” on electrooptical hybrid modulators, C. Malacrida is acknowledged for discussions. S. G.-V. thanks the MINECO for a FPU predoctoral fellowship (FPU17/04908) and CB-M for FPU fellowship (FPU16/02516). Computer resources, technical expertise and assistance provided by the SCBI (Supercomputing and Bioinformatics) centre of the University of Málaga are gratefully acknowledged. We thank the Vibrational spectroscopy lab (EVI) of the Research Central Services (SCAI) of the University of Málaga and John Pearson (BIONAND) for help with laser confocal microscopy analysis. We gratefully acknowledge the ICTS “NANBIOSIS” facilities, more specifically the U28 Unit of the Andalusian Centre for Nanomedicine & Biotechnology (BIONAND), for their help with the 2PA characterization and the microscopy studies.Peer reviewe