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To date, thermal nanoimprint lithography (NIL) for patterning hybrid perovskites has always involved an intricate etching step of a hard stamp material or its master. Here, we demonstrate for the first time the successful nanopatterning of a perovskite film by NIL with a low-cost polymeric stamp. The stamp consists of a dichromated gelatin grating structured by holographic lithography. The one-dimensional grating is imprinted into a perovskite film at 95 °C and 90 MPa for 10 min, resulting in a high quality second-order distributed feedback (DFB) laser. The laser exhibits an excellent performance with a threshold of 81 μJ/cm2, a line width of 0.32 nm, and a pronounced linear polarization. This novel approach enables cost-effective fabrication of high-quality DFB lasers compatible with different perovskite compositions and photonic nanostructures for a wide range of applications. We acknowledge the support of the Karlsruhe School of Optics & Photonics (KSOP) financed by the Ministry of Science, Research and the Arts of Baden-Wrttemberg as part of the sustainability financing of the projects of the Excellence Initiative II. We also acknowledge financial support through Germany’s Excellence Strategy via the Excellence Cluster 3D Matter Made to Order (3DMM2O, EXC-2082/1-390761711) and the Karlsruhe Nano Micro Facility (KNMFi). The group at the University of Alicante acknowledges financial support from the “Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación” (MCIN/AEI) of Spain, the European Regional Development Fund, European Social Funds (project PID2020-106114GBI00), and the Conselleria de Innovación, Universidades y Sociedad Digital de la Comunidad Valenciana (Grant No. AICO/2021/093). V.B. acknowledges financial support from the University of Alicante to perform a research stay at KIT in the frame of his PhD.

Large graphene-like molecules with four zigzag edges are ideal gain medium materials for organic near-infrared (NIR) lasers. However, synthesizing them becomes increasingly challenging as the molecular size increases. In this study, we introduce a new intramolecular radical-radical coupling approach and successfully synthesize two fused triangulene dimers (1a/1b) efficiently. X-ray crystallographic analysis of 1a indicates that there is no intermolecular π-π stacking in the solid state. When the more soluble derivative 1b is dispersed in polystyrene thin films, amplified spontaneous emission in the NIR region is observed. Using 1b as the active gain material, we fabricate solution-processed distributed feedback lasers that exhibit a narrow emission linewidth at around 790 nm. The laser devices also exhibit low thresholds with high photostability. Our study provides a new synthetic strategy for extended nanographenes, which have diverse applications in electronics and photonics. J.W. acknowledges financial support from the NRF Investigatorship Award (NRF-NRFI05-2019-0005), the A*STAR AME grant (A20E5c0089) and start-up grant from the Joint School of National University of Singapore and Tianjin University@Fuzhou. The group at the University of Alicante thanks financial support from the “Ministerio de Ciencia e Innovación” (MCIN) of Spain and the European Regional Development Fund (grant No. PID2020-119124RB-I00) and from the Generalitat Valenciana though grant No. AICO/2021/093. Besides, this study part of the Advanced Materials program supported by the Spanish MCIN with funding from European Union NextGenerationEU and by Generalitat Valenciana (grant no. MFA/2022/045). Z.S. is grateful to the financial support from National Natural Science Foundation of China (Grant No. 21971187, 22222110), Natural Science Foundation of Tianjin (19JCJQJC62700) and the Haihe Laboratory of Sustainable Chemical Transformations.

Donor–Acceptor (D–A) naphthalimides (NI) are highly fluorescent multitask compounds that have demonstrated success in a variety of optoelectronic applications, among which, thin film organic lasers (TFOLs) are not included. Here we assess the potential of various NI derivatives for lasing applications by investigating their amplified spontaneous emission (ASE) properties when dispersed in polystyrene thin films. To overcome the relatively low ASE photostability measured in the NIs, a series of peryleneimides (PI) derivatives, with similar chemical structure but with more extended π-conjugation, is synthesized and reported here, together with a complete characterization of their optical and ASE properties, both in solution and thin film. Most investigated compounds show ASE, with emissions at different wavelengths spanning from the blue to the red, depending on the derivative. Furthermore, surface emitting TFOLs with top-layer polymeric distributed feedback resonators are fabricated and characterized. This work represents an advance in the field of low-cost TFOLs, by including two families of successful laser dyes, NIs and PIs, the latter with significantly better photostability. The group at the University of Alicante acknowledges financial support from the “Ministerio de Ciencia e Innovación/Agencia Estatal de investigación” (MCIN/AEI) of Spain, European Regional Development Fund and European Social Funds (project PID2020-106114GB-I00) and from the Conselleria de Innovación, Universidades y Sociedad Digital de la Comunidad Valenciana (Grant No. AICO/2021/093). The team of the University of Castilla la Mancha acknowledges financial support from the MCIN/AEI of Spain (project PID2020-119636GB-I00 and RED2018-102331-T) and by FEDER Una manera de hacer Europa and Junta de Comunidades de Castilla-La Mancha (JCCM-FEDER) (SBPLY/17/180501/000189 and SBPLY/17/180501/000114). B. Donoso is grateful for a FPU predoctoral contract (FPU16/05099). I. Torres-Moya thanks to the Junta de Comunidades de Castilla-La Mancha for a post-doctoral contract (SBPLY/19/180501/000346). Finally, we acknowledge the computer resources, technical assistance, and expertise provided by the High Performance Computing Service of UCLM.

Perylenediimide (PDI) compounds with no substituents in their core are widely used as the active units of thin-film organic lasers. Recently, bay-substituted PDIs (b-PDIs) bearing two sterically hindering diphenylphenoxy groups at the 1,7-bay positions have received great attention because they show red-shifted emission with respect to bay-unsubstituted PDIs, while maintaining high photoluminescence (PL) quantum yields and low amplified spontaneous emission (ASE) thresholds even at high doping rates. However, their ASE photostability is relatively low compared to that of state-of-the-art PDIs. Thus, the design of b-PDIs with improved ASE photostability remains a challenge. Here, the synthesis of two b-PDIs with phenyl-type substituents at the imide positions is reported. Complete characterization of their optical properties, including absorption, PL, ASE, and transient spectroscopy, supported also by quantum chemical calculations, is performed with the dyes diluted in either a liquid solvent or a polystyrene film. Film experiments were accomplished at very low doping rates, to resemble the isolated molecule behavior, and also in a range of increasing doping rates, to investigate concentration quenching effects. The reported b-PDIs show improved ASE photostability (3-fold) with respect to b-PDIs with aliphatic-type substituents at the imide positions, whilst they show more propensity toward aggregation. The authors thank the Spanish Ministry of Economy and Competitiveness MINECO and the European Social Funds (project MAT2015-66586-R and FPI fellowship BES-2016-077681), the Ministry of Science and Innovation (MICINN) and the European FEDER funds (CTQ2016-77039-R, PGC2018-099568-B-I00, and PID2019-109200GB-I00, and Unidad de Excelencia María de Maeztu CEX2019-000919-M), and the Generalitat Valenciana (PROMETEO/2020/077 and SEJI/2018/035). J.A. acknowledges the MICINN for the “Ramón-y-Cajal” Fellowship (RyC-2017-23500).

Perylene‐fused, aggregation‐free polycyclic aromatic hydrocarbons with partial zigzag periphery (ZY‐01, ZY‐02, and ZY‐03) were synthesized. X‐ray crystallographic analysis reveals that there is no intermolecular π–π stacking in any of the three molecules, and as a result, they show moderate‐to‐high photoluminescence quantum yield in both solution and in the solid state. They also display the characteristic absorption and emission spectra of perylene dyes. ZY‐01 and ZY‐02 with a nearly planar π‐conjugated skeleton exhibit amplified spontaneous emission (ASE) when dispersed in polystyrene thin films. Solution‐processed distributed feedback lasers have been fabricated using ZY‐01 and ZY‐02 as active gain materials, both showing narrow emission linewidth (

Zigzag edged nanographenes such as peri-acenoacenes are promising materials for organic lasers, but the effects of heteroatom doping on the electronic properties and gain medium performance remain unclear. Herein, the facile synthesis of a new 1,2-oxaborine (BO) doped peri-tetracenotetracene derivative, the bis(1,2-oxaborine)peri-tetracenotetracene (BOTT-Mes), is reported. X-ray crystallographic analysis confirms the BO-doped planar structure and the nonexistence of intermolecular π–π stacking in solid state. Compared with the all-carbon peri-tetracenotetracene derivative (TT-Ar), the BO-doped BOTT-Mes exhibits more disrupted π-conjugation at the BO sites, a lower-lying highest occupied molecular orbital, and a larger energy gap. Due to its rigid skeleton and nonaggregative feature, it displays well-resolved absorption and emission spectra with a small Stokes shift (8 nm) and high photoluminescence quantum yield (80%) when it is dispersed in a polystyrene (PS) thin film. Notably, 1,2-oxaborine doping improves the film amplified spontaneous emission (ASE) performance, with a lower ASE threshold (Eth-ASE = 66 µJ cm–2) as compared to the TT-Ar doped PS film (Eth-ASE = 100 µJ cm–2). Furthermore, a low threshold (22 µJ cm–2) solution-processed distributed feedback laser is fabricated, indicating the feasibility of using BOTT-Mes as gain medium for practical laser applications. J.W. acknowledges financial support from A*STAR Advanced Manufacturing and Engineering grant (A20E5c0089) and National Research Foundation Investigatorship Award (NRF-NRFI05-2019-0005). The group at the University of Alicante acknowledges financial support from the “Ministerio de Ciencia e Innovación” of Spain, European Regional Development Fund and European Social Funds (PID2019-106114GB-I00 and BES-2016-077681) and from the Conselleria de Innovación, Universidades y Sociedad Digital de la Comunidad Valenciana (Grant No. AICO/2021/093).

We report the synthesis of a dibenzodinaphthocoronene (DBDNC) derivative as a novel nanographene with armchair, zigzag, and fjord edges, which was characterized by NMR and X-ray crystallography as well as infrared (IR) and Raman spectroscopies. Ultrafast transient absorption (TA) spectroscopy revealed the presence of stimulated emission signals at 655 nm and 710 nm with a relatively long lifetime, which resulted in dual amplified spontaneous emission (ASE) bands under ns-pulsed excitation, indicating the promise of DBNDC as a near-infrared (NIR) fluorophore for photonics. Our results provide new insight into the design of nanographene with intriguing optical properties by incorporating fjord edges. This work was financially supported by the Okinawa Institute of Science and Technology Graduate University (OIST), the Max Planck Society, JSPS KAKENHI Grant No. JP19K24686, and the European Union’s Horizon 2020 Research and Innovation program under grant agreement no. 101017821 (LIGHT-CAP). G. M. P thanks Fondazione Cariplo (Grant no. 2018-0979) for financial support. Researchers from the University of Alicante acknowledge support from the Spanish Ministerio de Ciencia e Innovación and the European Union (Next Generation EU) through grant no. PID2020-119124RB-I00; and to the Conselleria de Innovación, Universidades y Sociedad Digital de la Comunidad Valenciana (Grant No. AICO/2021/093).

A naphtho[2,1-b:6,5-b′]difuran derivative was found to serve as an effective violet-emitting laser dye. It showed amplified spontaneous emission at 413 nm with the threshold of 1.1–2.9 mJ cm−2 using 0.1–0.5 wt% in polystyrene film. Lasing was also demonstrated using all-polymeric distributed-feedback lasers emitting at 411–417 nm with the threshold of 2.0–2.9 mJ cm−2. This work was supported by JSPS KAKENHI grant JP19H05716 (to H. T.) and by the “Ministerio de Ciencia, Innovación y Universidades” of Spain, via grants MAT2015-66586-R and PID2020-119124RB-I00 and by the “Generalitat Valenciana” through grant AICO/2021/093.

The molecule N,N′-bis(3-methylphenyl)-N,N′-dyphenylbenzidine (TPD) has been widely used in optoelectronic applications, mainly for its hole-transporting properties, but also for its capability to emit blue light and amplified spontaneous emission, which is important for the development of organic lasers. Here, we report deep-blue-emitting distributed feedback (DFB) lasers based on TPD dispersed in polystyrene (PS), as active media, and dichromated gelatin layers with holographically engraved relief gratings, as laser resonators. The effect of the device architecture (with the resonator located below or on top of the active layer) is investigated with a dye (TPD) that can be doped into PS at higher rates (up to 60 wt%), than with previously used dyes (&lt, 5 wt%). This has enabled changing the index contrast between film and resonator, which has an important effect on the laser performance. With regards to thresholds, both architectures behave similarly for TPD concentrations above 20 wt%, while for lower concentrations, top-layer resonator devices show lower values (around half). Remarkably, the operational durability of top-layer resonator devices is larger (in a factor of around 2), independently of the TPD concentration. This is a consequence of the protection offered by the resonator against dye photo-oxidation when the device is illuminated with pulsed UV light.

High-transparency polymers, called optical polymers (OPs), are used in many thin-film devices, for which the knowledge of film thickness (h) and refractive index (n) is generally required. Spectrophotometry is a cost-effective, simple and fast non-destructive method often used to determine these parameters simultaneously, but its application is limited to films where h > 500 nm. Here, a simple spectrophotometric method is reported to obtain simultaneously the n and h of a sub-micron OP film (down to values of a few tenths of a nm) from its transmission spectrum. The method is valid for any OP where the n dispersion curve follows a two-coefficient Cauchy function and complies with a certain equation involving n at two different wavelengths. Remarkably, such an equation is determined through the analysis of n data for a wide set of commercial OPs, and its general validity is demonstrated. Films of various OPs (pristine or doped with fluorescent compounds), typically used in applications such as thin-film organic lasers, are prepared, and n and h are simultaneously determined with the proposed procedure. The success of the method is confirmed with variable-angle spectroscopic ellipsometry. Spanish Ministry of Economy and Competitivity (MINECO) and European Community (FEDER) through grant no. MAT2015-66586-R.

Introducción. Desde el Trabajo Social, con una perspectiva psicosocial, se investiga el acoso laboral (mobbing, acoso moral o acoso psicológico) en la estructura organizacional de los ayuntamientos españoles. Este punto de vista nos permite contemplar la realidad de las relaciones laborales desde una visión holística, integradora de los distintos aspectos que afectan al objeto de estudio. La prevalencia del acoso laboral en la Administración Pública española y los efectos nocivos de este problema justifican esta investigación. Dichos efectos se traducen tanto en problemas de salud para las personas afectadas como en la reducción de efectividad y productividad para las organizaciones. Se dispone de un importante volumen de datos empíricos sobre los antecedentes implicados en el proceso de acoso laboral. Sin embargo, no se han encontrado este tipo de investigaciones sobre los ayuntamientos. Existe un amplio acuerdo en las investigaciones psicosociales en señalar que factores como el poder y el liderazgo juegan un papel clave en el acoso en las relaciones laborales, considerando que el punto de partida está en el abuso de poder y, estrechamente ligado a él, determinados tipos de liderazgo. Por eso, este estudio ha analizado estos factores en la legislación actual. El objetivo es explorar sistemáticamente la configuración normativa de la estructura organizacional de los ayuntamientos, para analizar su relación con los factores involucrados en la aparición del acoso laboral, específicamente el poder y el liderazgo. Metodología. Para ello, la metodología utilizada es el Análisis de Contenido. Se analizan todas las normas que establecen la estructura organizacional del ayuntamiento, teniendo en cuenta todas las áreas en las que sus recursos humanos pueden verse afectados. Resultados. Los resultados muestran que la regulación actual de la estructura organizacional de los ayuntamientos no trata la prevención del acoso laboral en cuanto a los factores poder y liderazgo y que resulta compatible con la aparición del problema. Discusión. Se discuten las posibilidades de intervención eficaz contra el acoso en la actual estructura de la entidad. Conclusiones. Se concluye que, el tratamiento formal que se da a estos factores en la legislación que establece la organización y estructura de los ayuntamientos, permite la promoción del problema que se investiga. Introduction. A Social Work study was conducted from a psychosocial perspective, examining workplace harassment (mobbing, either moral or psychological) within the organisational structure of Spanish city councils. Such a point of view allowed us to reflect on the factual reality of labour relations adopting a holistic approach, and thus integrating the different aspects that affected the object of study. In addition, the prevalence of mobbing in the Spanish Public Administration and the harmful effects of this phenomenon justified the present study. Workplace mobbing effects eventually become inherent health problems. They affect the bullied and lower the effectiveness and productivity of their work in these local organisations. A significant volume of empirical data exists on the antecedents of workplace bullying. No studies, however, have hitherto been conducted on this topic in the context of the administrative offices of the local government. There is also a broad agreement in psychosocial research that factors such as power and leadership play critical roles in the emergence of harassment in labour relations: the starting point is considered to be power abuse and, closely linked to it, certain types of leadership misuse. Hence, this study analysed the factors mentioned above in Spain’s current legislation. The goal was to systematically explore the normative configuration of the organisational structure of municipalities and analyse its connection with the factors involved in the appearance of workplace bullying, specifically those linked to the exercise of power and leadership. Methodology. The methodology used was content analysis. The regulations establishing a city council’s organisational structure were analysed, considering all the human resources domains which could be potentially affected. Results. The results show that the current regulation of the organisational structure of city councils does not address the prevention of workplace bullying in terms of power or leadership factors, despite the latter being linked to the appearance of the problem. Discussion. The possibilities of effective intervention against mobbing in the entity’s current structure are discussed. Conclusions. To conclude, the formal treatment given to the factors exposed above within the legislation regulating the organisation and structure of city councils encourages mobbing.

The search of compounds emitting in the near-infrared (NIR) has been accelerated owing to their use in biomedical and telecommunications applications. In this regard, nanographenes (NGs) are attractive materials adequate for integration with other technologies, which have recently demonstrated amplified spontaneous emission (ASE) and lasing across the visible spectrum. Here, the optical and ASE properties of four-zigzag edged NGs of the [m,n]peri-acenoacene family are reported, whose size is increased through conjugation extension by varying n (from 3 to 5) while keeping m = 2. Results show that such 1D conjugation extension method is more efficient in terms of shifting the photoluminescence (PL) to the infrared (PL at 710 nm in the larger compound, PP-Ar) than through 2D conjugation extension as in previously reported NGs (PL at 676 nm with the largest compound FZ3, with n = 3 and m = 4). Additionally, PP-Ar shows dual-ASE (at 726 and 787 nm), whose origin is elucidated through Raman and transient absorption spectroscopies. These compounds’ potential for red and NIR lasing is demonstrated through the fabrication of distributed feedback lasers with top-layer resonators. This study paves the way towards the development of stable low-cost all-plastic NIR lasers. The authors acknowledge financial support from the “Ministerio de Ciencia, Innovación y Universidades” of Spain, European Regional Development Fund and European Social Funds (MAT2015-66586-R, PDI2019-106114GB-I00, BES-2016-077681, PGC2018-098533-B-100 and RED2018-102815-T). J.C. thanks the Junta de Andalucía of Spain (UMA18FEDERJA057). The authors also thank the Research Central Services (SCAI) of the University of Málaga. F.G. acknowledges the Spanish Government for an FPI grant. G.M.P. thanks Fondazione Cariplo (grant no 2018-0979) for the financial support. J.W. acknowledges the “Agency for Science, Technology and Research of Singapore” for financial support from A*STAR AME grant (A20E5c0089). A.M.R. and F.S. have received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. [816313]).

The spectral overlap between stimulated emission (SE) and absorption from dark states (i.e. charges and triplets) especially in the near-infrared (NIR), represents one of the most effective gain loss channel in organic semiconductors. Recently, bottom-up synthesis of atomically precise graphene nanostructures, or nanographenes (NGs), has opened a new route for the development of environmentally and chemically stable materials with optical gain properties. However, also in this case, the interplay between gain and absorption losses has hindered the attainment of efficient lasing action in the NIR. Here, we demonstrate that the introduction of two fluoranthene imide groups to the NG core leads to a more red-shifted emission than the precursor NG molecule (685 vs. 615 nm) and also with a larger Stokes (45 nm vs. 2 nm, 1026 cm-1 vs. 53 cm-1, respectively). Photophysical results indicate that, besides the minimisation of ground state absorption losses, such substitution permits to suppress the detrimental excited state absorption in the NIR, which likely arises from a dark state with charge-transfer character. This has enabled NIR lasing (720 nm) from all-solution processed distributed feedback devices with one order of magnitude lower thresholds than those of previously reported NIR-emitting NGs. This study represents an advance in the field of NGs and, in general, organic semiconductors photonics, towards the development of cheap and stable NIR lasers. G.M.P. thanks Fondazione Cariplo for financial support (grant n° 2018-0979). R.M.M., P.G.B., J.M.V., J.A.Q. and M.A.D.G. acknowledge funding from the Spanish Ministry of Economy and Competitiveness (MINECO), the European Regional Development Fund (FEDER) and European Social Funds (ESF; grant n° MAT2015-66586-R and FPI fellowship BES-2016-077681). Q.C., K.M. and A.N. are grateful for the financial support by the Max Planck Society and the ANR-DFG NLE Grant GRANAO by DFG 431450789. K.M. acknowledges a fellowship from Gutenberg Research College, Johannes Gutenberg University Mainz. R.K. and A.N. appreciate the support by the Okinawa Institute of Science and Technology Graduate University. Y.I. and A.N acknowledge financial support from the Japan Society of Promotion Science Program for Advancing Strategic International Networks to Accelerate the Circulation of Talented Researchers.

All‐solution processed surface‐emitting organic distributed feedback lasers are attractive devices for low‐cost applications. Here, lasers emitting in the spectral region between 375 and 475 nm, in which both active material and resonator (1D relief gratings) are based on solution‐processable polymer films, are reported. Ten different organic compounds dispersed in polystyrene are used as active layers of the prepared devices. They include various carbon‐bridged oligo(p‐phenylenevinylene) (COPVn, with n = 1,2) derivatives and two terfluorene compounds. The synthesis and complete optical and amplified spontaneous emission properties of one of the COPV1 compounds, COPV1(Me)‐t‐Bu, designed for deep‐blue emission, are also included. The feasibility of the resonator fabrication, performed by holographic lithography with a dichromated gelatine photoresist over the active film, is successfully demonstrated for all devices. Remarkably, no resolution limitations are found even for the lowest grating period (235 nm) required for the fabrication of the laser based on COPV1(Me)‐t‐Bu. It is also demonstrated that the rectangular grating profile with duty cycle 0.75:0.25 (hill:valley) is very convenient to optimize the resonator efficacy. The Spanish team acknowledges support from the Spanish Government (MINECO) and the European Community (FEDER) through Grant No. MAT2015-66586-R. H.T. and E.N. thank the financial support from MEXT (JP19H05716 for H.T. and JP19H0549 for E.N.).

The efficient synthesis and electronic properties of two large‐size cove‐edged nanographenes (NGs), CN1 and CN2, are presented. X‐ray crystallographic analysis reveals a contorted backbone for both molecules owing to the steric repulsion at the inner cove position. Noticeably, the dominant structures of these molecules contain four (for CN1) or six (for CN2) localized C=C double bonds embedded in nine (for CN1) or twelve (for CN2) aromatic sextet rings according to Clar's formula, which is supported by bond length analysis and theoretical (NICS, ACID) calculations. Furthermore, Raman spectra exhibit a band associated with the longitudinal CC stretching mode of olefinic double bonds. Owing to the existence of the additional olefinic bonds, both compounds show a small band gap (1.84 eV for CN1 and 1.37 eV for CN2). They also display moderate fluorescence quantum yield (35 % for CN1 and 50 % for CN2) owing to the contorted geometry, which can suppress aggregation in solution. J.W. acknowleges financial support from the MOE Tier 3 programme (MOE2014-T3-1-004) and NRF Investigatorship (NRF-NRFI05-2019-0005). J.C. acknowledges MINECO and Junta de Andalucía of Spain projects (PGC2018-098533-BI00 and UMA18FEDERJA057). M.A.D.-G. and R.M.-M. thank support from MINECO through the research project MAT2015-66586-R and the FPI fellowship (no. BES-2016-077681), respectively.

Chemically synthesized zigzag-edged nanographenes (NG) have recently demonstrated great success as the active laser units in solution-processed organic distributed feedback (DFB) lasers. Here, we report the first observation of dual amplified spontaneous emission (ASE) from a large-size NG derivative (with 12 benzenoid rings) dispersed in a polystyrene film. ASE is observed simultaneously at the 685 and 739 nm wavelengths, which correspond to different transitions of the photoluminescence spectrum. Ultrafast pump-probe spectroscopy has been used to ascertain the underlying photophysical processes taking place in the films. DFB lasers, based on these materials and top-layer nanostructured polymeric resonators (i.e., one or two-dimensional surface relief gratings), have been fabricated and characterized. Lasers emitting close to either one of the two possible ASE wavelengths, or simultaneously at both of them, have been prepared by proper selection of the resonator parameters. The Alicante team was funded by Spanish Government (MINECO) and European Community (FEDER), grant number MAT2015-66586-R. The researcher R.M-M was funded by a MINECO FPI fellowship (No. BES-2016-077681). The Singapore team was funded by the NRF Investigatorship programme (NRF-NRFI05-2019-0005). The Milan team has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 816313). G.M.P. acknowledges funding from Fondazione Cariplo, grant No. 2018-0979. C.D. and S.S. acknowledge funding from ERC Starting Grant SOLENALGAE (No. 679814).

10 pags., 7 figs., The increasing number of solution-processed laser compounds that can be implemented as low-cost, flexible, and/or integrated devices, makes necessary the development of reliable methods to delineate all their amplifying signatures and thus to open the door to appropriate cross-sample comparisons. Seeking to solve this problem, a new formalism to retrieve the losses and the optical gains from Amplified Spontaneous Emission (ASE) spectra as a function of the excitation density has been recently reported. In this manuscript, we explore the potential of this methodology to unveil relevant information on the photonic properties of the waveguiding devices and on the photophysics of the active materials. We demonstrate that the Variable Pump Intensity method opens the door to understand the relationship between the ASE thresholds and the optical gains and losses, it enables the extraction of the scattering/modal losses of the passive devices, and it can unveil the presence of leaky-modes and excited state absorption. In contrast, it does not perform too well in samples with multiple active species in its current implementation. We have substantiated all these findings using organic semiconductor thin films, several dye-doped polymer thin films and solutions of boron hydride., The researchers from the University of Alicante and LC acknowledge financial support from the Spanish Ministerio de Economía y Competitividad (MINECO) and the European FEDER funds through Grant numbers MAT2015-66586-R and MAT2017-83856-C3-1, respectively.

Carbon-bridged oligo(p-phenylenevinylene)s (COPVn with repeating unit n = 1–6) have demonstrated great success as laser dyes for thin-film organic lasers. The excellent photostability observed in the longer homologues is, however, not present in the blue-emitting shorter compounds COPV1 and COPV2, attributed to the unprotected terminal positions that can degrade by photoreaction in the excited state. Here we report the synthesis of various COPV1 and COPV2 derivatives functionalized at the terminal positions with two types of sterically bulky protecting substituents: Tip (2,4,6-triisopropylphenyl) and tert-butyl (t-Bu) groups. Such molecular designs aim at preventing such photodegradation processes and thus to improve their stability. The efficacy of kinetic isotope effect for stabilization is also examined for COPV2, by the addition at terminal positions of deuterium atoms. Absorption, photoluminescence (PL), including PL quantum yield, and amplified spontaneous emission (ASE) studies have been conducted in polystyrene films doped with each of the derivatives. Significant and slight improvements of the ASE photostability are observed for the compounds with Tip groups and deuterium, respectively. Installation of substituents slightly affects the ASE wavelength within the blue spectral region, that is 385–413 nm and 462–474 nm, for COPV1 and COPV2, respectively. Financial support from Spanish Ministerio de Economía y Competitividad (MINECO) and the European FEDER funds through Grant MAT2015-66586-R is gratefully acknowledged. This work was partially supported by MEXT and JSPS KAKENHI Grant Numbers JP16H04106 and JP19H05716 to HT and JP19H0549 to EN.

Electrochemically generated chemiluminescence (ECL) from solid-state poly(9,9′-octylfluorene) films was obtained by the successive electrochemical injection of polarons with opposite sign (annihilation ECL) in double potential steps. The processes involved in the recombination of polarons, the quenching of the electrochemically generated excitons, and the emission stability have been also analyzed. A systematic study at various electrochemical potentials has been carried out to determine optimal conditions to obtain a maximum ECL intensity, particularly with potentials of 0.4 V beyond the doping onsets (for both p- and n-doping). Results show that while the ECL emission is slightly affected by the potential of the emission, it is strongly dependent on the charging potential. Under large charging potential, the electrochemically generated excitons formed in the emission step get quenched by an excess of polarons and bipolarons that are detrimental to ECL. The maximum emission is obtained when the applied potentials are 0.4 V over the doping onset of the polymer conjugated chain. After partial depletion of the excess of polarons, the emission coming from the recombination of balanced polarons of opposite sign is observed. The stability of ECL emission in the optimal range was determined in continuous cathodic–anodic pulses. A rapid loss of the intensity in the initial stages is observed due to the dissolution of low molecular weight polymer fragments that become soluble upon electrochemical doping. The emission spectrum remains stable during the complete lifetime of the polymer. The spectral shape of PFO films indicates that the emission occurs mainly from the β-phase domains in which the electrochemical charge is preferentially injected. Authors acknowledge financial support from the Spanish Ministry of Economy Explora Ciencia Project MAT2013-49534-EXP.

Organic light emitting diodes (OLEDs) are current-driven devices that utilize light emission from excited states of molecules.(1) Operating OLEDs involves charge injection from the anode and the cathode into the adjacent organic layers, transport of injected charge carriers through the organic layers, and exothermic recombination of holes and electrons to generate electronically excited states of molecules. Subsequent deactivation of molecules produces electroluminescence (EL) that goes out of the device. Attaining high quantum efficiency for EL requires: (i) efficient charge injection from both electrodes into the adjacent organic layers at low drive voltage, (ii) charge balance, and (iii) confinement of charge carriers within the emitting layer to increase the probability of emissive recombination. The insertion of hole-acceptor and electron-acceptor layers between the electrodes and the emitting layer substantially increases efficiency. A multilayer structure of OLED’s consists of the emitting layer sandwiched between hole- and electron-acceptor layers that in turn are in contact with the metallic anode and cathode, respectively. Amorphous molecular materials have been proven to show several characteristics that qualify them as excellent materials to be used in OLED’s.(1) Their most remarkable feature is that, due to their homogeneous and isotropic properties, they form smooth thin films, allowing uniform contact with the metallic electrodes and between organic layers. An issue concerning nomenclature is here worthy of comment. As stated above, device operation involves three main processes, namely, charge injection, charge transport, and light emission. Although in this work we will only focus on the first, we shall also use the accepted terminology of hole- or electron-transporters, being aware of the fact that the correct one would be “acceptors” instead of ‘transporters” (investigating their transport performance(2) would require considering also carrier mobility). Hereafter both terminologies will be used indifferently., Financial support by the Spanish “Ministerio de Economía y Competitividad MINECO” and the European Union through FEDER funds (Grants FIS2012-35880, FIS2015-64222-C2-1-P, FIS2015-64222-C2-2-P, and MAT2015-66586-R) and the Universidad de Alicante, is gratefully acknowledged.

Carbon-bridged bis(aminoaryl) oligo(para-phenylenevinylene)s have been prepared and their optical, electrochemical, and structural properties analyzed. Their radical cations are class III and class II mixed-valence systems, depending on the molecular size, and they show electronic couplings which are among the largest for the self-exchange reaction of purely organic molecules. In their dication states, the antiferromagnetic coupling is progressively tuned with size from quinoidal closed-shell to open-shell biradicals. The data prove that the electronic coupling in the radical cations and the singlet–triplet gap in the dications show similar small attenuation factors, thus allowing charge/spin transfer over rather large distances. ·, We thank MINECO of the Spanish Government (CTQ2015- 69391-P, CTQ2013-40480-R and MAT2015-66856-R) for their support. We also thank the Research Central Services (SCAI) of the University of M#laga. This work is partially supported by Grant-in-Aid for Scientific Research (16H04106 to HTand 15H05754 to EN) and the Strategic Promotion of Innovative Research, JST (to EN) from MEXT, Japan. M.H. and C.L. are grateful to the Deutsche Forschungsgemeinschaft for supporting this work (GRK 2112).

Surface-emitting distributed feedback (DFB) lasers with both, resonator and active material based on solution-processable polymers, are attractive light sources for a variety of low-cost applications. Besides, the lasers should have competitive characteristics compared to devices based on high-quality inorganic resonators. Here, we report high performing all-solution-processed organic DFB lasers, consisting of water-processed photoresist layers with surface relief gratings located over the active films, whose emission properties can be finely tuned through resonator design. Their laser threshold and efficiency are simultaneously optimized by proper selection of residual resist thickness and grating depth, d. Lowest thresholds and largest efficiencies are obtained when there is no residual layer, while a trade-off between threshold and efficiency is found in relation to d, because both parameters decrease with decreasing d. This behaviour is successfully explained in terms of an overlap factor r, defined to quantify the interaction strength between the grating and the light emitted by the active film and traveling along it, via the evanescent field. It is found that optimal grating depths are in the range 100–130 nm (r ~ 0.5−0.4). Overall, this study provides comprehensive design rules towards an accurate control of the emission properties of the reported lasers.

The design, synthesis and evaluation of the amplified spontaneous emission (ASE) properties of a series of arylalkynyl-benzo[c][1,2,5]thiadiazole (BTD) and [1,2,5]thiadiazolo[3,4-g]quinoxaline (TDQ) derivatives are described. The synthetic strategy entailed the use of Sonogashira and Stille reactions based on the different aromatic natures of the two cores. The ASE properties were measured in thin polystyrene (PS) films doped with different concentrations of the synthesised compounds. BTD derivatives showed narrowing of the photoluminescence spectra (PL), thus revealing their potential laser applications. Only one TDQ derivative showed ASE. X-ray diffraction analysis was carried out to understand the observed results and to establish structure–property relationships. Molecules that showed strong molecular packing quenched the PL emission, thus giving rise to higher ASE thresholds. This is the first study in which ASE has been studied in BTD and TDQ derivatives and it represents a step forward in understanding this class of compounds for laser applications. The Alicante team acknowledges support from Ministerio de Ciencia, Innovación y Universidades, Spain, under projects MAT2015-66586-R (MINECO/FEDER), FIS2017-82919-R (MINECO/AEI/FEDER,UE) and FIS2015-66570-P (MINECO/FEDER). The authors acknowledge financial support from the Junta de Comunidades de Castilla-La Mancha (JCCM-FEDER) (project SBPLY/17/180501/000189), the Spanish Ministry of Economy and Competitiveness (CTQ2013-45415P) and Gobierno Vasco-Eusko Jaularitza (IT-673-13). R. Martı´n is grateful to the MEC for an FPU studentship.

Currently, mineral additions are widely used as they favor not only the partial replacement of Portland cement, they reduces clinker production, but also provide certain chemical and physical properties that make concrete more durable. The variation of the water-cement ratio, the use of setting retarding additives and the addition of Cementitious Supplementary Materials (MCS) are factors that have a great influence on the hydration of the cement and the formation of the phases of a hydrated cement paste. That is why this research focuses on evaluating the effect of the active mineral addition of calcined clay, limestone and gypsum (LC2), in the cement hydration process. The work consists of several stages: first, a study is made of the variations that are made to the water to define the protocol and the amount of addition to study (30%); In a second stage, calorimetry and chemical shrinkage tests are carried out on cement pastes and a final stage where the influence of the addition on the hydration processes of the pastes is analyzed. This research provides a way of replacing Portland cement through the use of mineral additions, as is the case of LC2, which are in turn within the Construction Industry, to be a sustainable way of production of materials in Cuba.

The Supplementary Cementitious Materials (MCS) are currently, together with the additives, the most sustainable solutions that are worked to achieve high performance concrete and more resistant to aggressive environments. This research focuses on the introduction of additions in the hotel buildings of Cayo Santa Maria, Cuba. With previous studies showing that some additions can decrease the appearance of cracks due to retraction, a phenomenon very common in the coastal areas of the country, it is decided to begin a research focused on tackling cracking of concrete. The aim is to evaluate the introduction of LC2 (calcined clay, limestone and gypsum) as an active mineral addition concrete. The work is divided into two stages in order to evaluate the introduction of LC2 as an addition. In the first stage, the protocol a of the research is defined, the work is specified with 30% addition, in the second stage the tests are carried out to determine the properties of the fresh concrete as a consistency by the Cone de Abrams, in state hardened, resistance at 7 and 28 days and retraction by ASTM C-157. In this way, a study is made available on the effect of the LC2 addition on the properties of fluid concretes and it is possible to reduce the consumption of cement so harmful to the environment, as well as to make available to the construction a new affordable material in Cuba.

The standard procedure to identify the hole- or electron-acceptor character of amorphous organic materials used in OLEDs is to look at the values of a pair of basic parameters, namely, the ionization potential (IP) and the electron affinity (EA). Recently, using published experimental data, the present authors showed that only IP matters, i.e., materials with IP &gt, 5.7 (&lt, 5.7) showing electron (hole) acceptor character. Only three materials fail to obey this rule. This work reports ab initio calculations of IP and EA of those materials plus two materials that behave according to that rule, following a route which describes the organic material by means of a single molecule embedded in a polarizable continuum medium (PCM) characterized by a dielectric constant &epsilon, PCM allows to approximately describe the extended character of the system. This &ldquo, compound&rdquo, system was treated within density functional theory (DFT) using several combinations of the functional/basis set. In the preset work &epsilon, was derived by assuming Koopmans&rsquo, theorem to hold. Optimal &epsilon, values are in the range 4.4&ndash, 5.0, close to what is expected for this material family. It was assumed that the optical gap corresponds to the excited state with a large oscillator strength among those with the lowest energies, calculated with time-dependent DFT. Calculated exciton energies were in the range 0.76&ndash, 1.06 eV, and optical gaps varied from 3.37 up to 4.50 eV. The results are compared with experimental data.

La nueva sociedad del conocimiento requiere nuevas competencias para los docentes del siglo xxi. Una de las competencias clave son las conocidas como las competencias digitales, que todo estudiante debe haber adquirido una vez acabada la enseñanza obligatoria. Por tanto, se hace necesario que los docentes estén preparados para crear los escenarios que propicien la adquisición de estas competencias. El objetivo del presente artículo es un primer acercamiento al Plan de Innovación Tecnológica en la Educación (PITE) con el fin de introducir mejoras en él. Se trata de un estudio basado en un diseño de encuesta, cuya muestra la constituyen estudiantes de las titulaciones de grado de Maestro en Educación Infantil y Primaria de la Universidad Católica de Valencia San Vicente Mártir, seleccionados mediante un muestreo no probabilístico y accidental en el que se recoge la información mediante un cuestionario. Los resultados señalan que los estudiantes están satisfechos con el plan y consideran que ha mejorado tanto su competencia digital como la digital docente. Se sugiere que se utilicen estándares y descriptores a la hora de diseñar las acciones formativas sobre la competencia digital docente en la formación inicial de los maestros y, a partir ello, se podrá evaluar y acreditar el nivel competencial y su progreso. The new knowledge society requires new competences for teachers of the 21st century. One of the key competences are those known as digital, which every student must have acquired once the compulsory education is finished. The aim of this article is a first approach to the Plan of Technological Innovation in Education (PITE) in order to introduce improvements in it. This is a study based on a survey design, whose sample is constituted by students of the degrees of Teacher of Pre-school and Primary Education at the Catholic University of Valencia, selected by a non-probabilistic and accidental sampling, in which information is collected by means of two questionnaires. The results point out that students are satisfied with the plan and that they consider both their digital competence and digital teaching have improved. It is suggested that standards and descriptors should be used when designing training actions on teacher digital competence in the initial training of teachers and, so that it can be evaluated and accredited the competence level and its progress. Educación

The chemical synthesis of nanographene molecules constitutes the bottom-up approach toward graphene, simultaneously providing rational chemical design, structure-property control and exploitation of their semiconducting and luminescence properties. Here, we report nanographene-based lasers from three zigzag-edged polycyclic aromatics. The devices consist of a passive polymer film hosting the nanographenes and a top-layer polymeric distributed feedback resonator. Both the active material and the laser resonator are processed from solution, key for the purpose of obtaining low-cost devices with mechanical flexibility. The prepared lasers show narrow linewidth (, Chemically synthesized graphene nanosheets offer device design flexibility and improved optoelectronic performance. Here, the authors report solution-processed distributed feedback lasers with graphene nanosheets as active media having linewidths

Background Oral mucositis (OM) is an inflammatory reaction of the oropharyngeal mucosa to cumulative chemotherapy (CT) and radiation therapy (RT), affecting one or more parts of the digestive tract along with the quality of life (QoL) of the patient. The goal of this study was to identify valid and reliable tools to evaluate QoL related to OM. Methods A systematic review of the literature was conducted up to May 2016. Articles were selected by peers using the PubMed database through a search following the inclusion and exclusion criteria and STAndards for the Reporting of Diagnostic accuracy studies (STARD) checklist with a cut-off point ≥ 70%. Results We identified four relevant articles that described instruments to assess the QoL related to OM in patients undergoing cancer treatment. Conclusions The evaluation of the QoL in patients with OM is a difficult scenario because of its multiple variables. The knowledge of this relationship is limited because general instruments of oral health or cancer therapy are commonly used for evaluation. However, valid instruments are already available for estimating the impact of OM on the QoL from the patient's perspective.

Thin-film organic lasers are attractive light sources for a variety of applications. Recently, it is reported that carbon-bridged oligo(p-phenylenevinylene)s (COPVn with repeating unit n = 1–6) function as unique laser dyes which combine high fluorescence efficiency, wavelength tunability, and both thermal and photostability, making them ideal for use in organic semiconductor lasers. However, in order to obtain such excellent properties, COPVn require blending in a matrix, such as a thermoplastic polymer, thus leading to miscibility issues, limited absorption, and charge transporting properties. Here, high-performance lasers with a novel active polymer poly-COPV1, based on the basic unit of COPV1 and prepared as a high-quality neat film, are reported which overcome the trade-off between the device performance and durability. The prepared lasers show thresholds 30 times lower and operational lifetimes 300 times longer than devices based on COPV1 dispersed in polystyrene. The low threshold operation allows the poly-COPV1 lasers to be pumped by a nitride diode laser., Spanish Government (MINECO). Grant Numbers: MAT2011-28167-C02-01, MAT2015-66586-R European Community (FEDER) MINECO FPI Fellowship. Grant Number: BES-2009-020747 Junta de Castilla y León (JCYL) Postdoctoral Fellowship. Grant Number: SA046U16 MEXT. Grant Numbers: 16H04106, 15H05754 Engineering and Physical Sciences Research Council. Grant Numbers: EP/K503162/1, EP/J009016/1 Royal Society Wolfson Research

Latest advances from our research group towards improving the performance of solution-processed distributed feedback lasers will be discussed. They include advances on the laser material and the resonator and their application as optical sensors.

Perylenediimide (PDI) dyes dispersed in polymer films have demonstrated great success as active materials in thin-film organic lasers (TFOLs). The type of matrix used to host the dye and the dye doping rate are both crucial parameters to optimize laser performance. This work reports the study of two soluble PDIs, the comercial derivative perylene orange (PDI-O) emitting at around 580 nm, and a new dye (b-PDI-A) with substituents at the 1,7 bay positions of the PDI core emitting at around 620 nm, dispersed at different doping levels (up to 8 and 50 wt %, for PDI-O and b-PDI-A, respectively) in two widely used polymers for optoelectronics, polystyrene (PS) and poly(methyl methacrylate) (PMMA). The main goal is to determine which of these two polymers, and at which dye concentration, provides the best results for their use in TFOLs. The assessment of the active materials has been carried out through the analysis of their absorption, photoluminescence, and amplified spontaneous emission (ASE) properties. Their capability to form high-quality optical waveguides has also been studied by determining gain coefficients and waveguide losses. Results have shown that for both types of PDI derivatives PS is better than PMMA at any concentration, which means larger photoluminescence efficiency, lower ASE thresholds, longer ASE operational lifetimes, larger gain, and lower propagation waveguide losses. In addition, the onset concentration at which dye aggregation becomes significant as to negatively affect the optical properties is lower in PMMA than in PS; thus, the larger the blending ratio, the larger the superiority of PS with respect to PMMA is. Financial support from Spanish Ministerio de Economía y Competitividad (MINECO) and the European FEDER funds through Grants MAT2015-66586-R and CTQ2016-77039-R (AEI/FEDER, UE) is gratefully acknowledged. R.M-M is supported by a MINECO FPI contract (no. BES-2016-077681). M.A.D-G acknowledges support from the University of Alicante and to the Spanish Ministry of Education (grant no. PR2015-00390) to perform a sabbatical stay at UCSB.

Perylene bisimides (PBIs) are n-type semiconducting and photogenerating materials widely used in a variety of optoelectronic devices. Particularly interesting are PBIs that are simultaneously water-soluble and liquid-crystalline (PBI-W+LC) and, thus, attractive for the development of high-performing easily processable applications in biology and “green” organic electronics. In this work, singular temperatures connected to charge transport mechanism transitions in a PBI-W+LC derivative are determined with high accuracy by means of temperature-dependent photocurrent studies. These singular temperatures include not only the ones observed at 60 and 110 °C, corresponding to phase transition temperatures from crystalline to liquid-crystalline (LC) and from LC to the isotropic phase, respectively, as confirmed by differential scanning calorimetry (DSC), but also a transition at 45 °C, not observed by DSC. By analyzing the photocurrent dependence simultaneously on temperature and on light intensity, this transition is interpreted as a change from monomolecular to bimolecular recombination. These results might be useful for other semiconducting photogenerating materials, not necessarily PBIs or even organic semiconductors, which also show transport behavior changes at singular temperatures not connected with structural or phase transitions. We appreciate support from the Spanish government (MINECO) and the European Community (FEDER) through Grant MAT-2011-28167-C02-01, as well as the University of Alicante. We gratefully acknowledge financial support from MINECO (MAT2014-52305-P) and the UCM-BSCH joint project (GR3/14-910759). A. de la Peña thanks Universidad Complutense for a predoctoral fellowship.

Two-dimensional (2D) distributed feedback (DFB) lasers with gratings imprinted by thermal nanoimprint lithography on the active film are reported. They show thresholds for lasing of ∼10 kW/cm2, similar to the most efficient imprinted DFB lasers reported; and long operational lifetimes (under ambient conditions) of ∼12 × 104 pump pulses. The key for their successful operation has been the selection of a highly efficient and stable dye, perylene orange (PDI-O), and a proper matrix to host it, the fluoro-modified thermoplastic resist mr-I7030R, which has enabled 2D imprinting while preserving the dye optical properties. The use of the UV-curable resist SU8 as an alternative matrix for PDI-O to be imprinted by combined nanoimprint and photolithography was also investigated, and was concluded to be unsuccessful due to severe photoluminescence quenching. By replacing PDI-O with Rhodamine 6G, lasers with reasonable thresholds, but with significantly inferior operational lifetimes in comparison to PDI-O/mr-I7030R devices, were obtained., We thank support from the Spanish Government (MINECO) and the European Community (FEDER) through Grants MAT2011-28167-C02 and MAT2015-66586-R, as well as to the University of Alicante. M.M-V. has been partly supported by a MINECO FPI fellowship (no. BES-2009-020747) and by a Junta de Castilla y León grant (no. SA046U16).