Contribution to characterization of last-generation photodetectors and improvement of their efficiency using micro and nanostructures

Mención Internacional en el título de doctorThe world is going through constant technological changes, and what it seems to be a great improvement to the life in Earth at one moment, can lead to disastrous effects in the future. This has happened several times during the human being history, and one clear example is the climate change, global warming, and greenhouse effect. Since the industrial revolution, the humanity went through several technological changes: some of them allowed us to progress as a civilization, but others will lead us to self-destruction. A recent example is the release of chlorofluorocarbon (CFC) gases that destroyed a huge part of the ozone layer at the Earth’s poles. Nowadays, one of the big problems that we are facing is the massive amount of carbon dioxide that we are throwing into atmosphere, mainly due to the energy generation activities. That is why this thesis is focused on increase the efficiency of devices that produce energy in a cleaner way, using solar energy. Doing so, in a near future we will be able to replace the actual contaminating energy sources for cleaner, non-emitting, renewable energy sources. Of course, this topic is too general, so this work is split in three big sections, intending to give full coverage to the topic. The first section is based onto the building blocks of solar harvesting, i.e., the solar cells. The more mature technology, commercially available is the silicon-based solar cell, but in the last years, a lot of technologies were also developed such as organic photovoltaics or perovskites. Each of these technologies have their own fabrication procedure, being the silicon very expensive and high energy demanding, while in the case of organic or perovskite the fabrication procedures are usually solvent-based and cheaper in terms of energy and material costs. After a brief explanation of the most used thin-film deposition techniques (used on organics and perovskites) the building process of a methylammonium lead iodide perovskite is explained step by step. This fabrication gave a resulting solar cell with a power conversion efficiency of 16.9%. Due to the environmental issues that this novel material can cause (mainly because it has lead in its composition), a lead-free perovskite was also studied (cesium tin iodide). The conclusion extracted from this study is that this lead-free perovskite could have very interesting applications, for example in smart windows, but their electrical conductivity problems should be solved first. Ending with this section, a proof of concept including organic and perovskite photodetectors into a visible light communication system was carried out, resulting in both technologies being able to perform good enough to be part of an audio link (with a bandwith higher than 40 kHz). Once we have a device to work with, in order to stablish their properties, it should be characterized. That is what the second section is about. This characterization must be done in a standardized way, under certain conditions and circumstances. One of these conditions is to have a stable, well-defined illumination source, that can recreate the standard AM1.5G spectrum (which is the spectrum of light that arrives at the Earth’s surface, coming from the Sun). All this restrictions and parameters that dictates whether a light source is valid for this process or not are defined by the International Electrotechnical Commission under the standard IEC 60904-9. During this thesis, due to the necessity of this light to characterize devices, we decided to create one. This gave birth to SUNBOX, our proprietary solar simulator. SUNBOX belongs to a AAA-Class according to the IEC standard, which represents the highest quality possible in solar simulators. It is fully based on light emitting diodes and also customizable, with a tunable spectrum that can go from 0.2 to 1.2 suns and has 14 different wavelengths that can be intensity-tuned freely. It is also clearly distinguishable from the commercial ones because its structure is 3D-printed, so it is lightweight and has a low cost. Due to the intellectual property protection as a utility model, only a brief part regarding the electronic design is explained in this document, together with the calibration procedure that was carried out in terms of spectral match, homogeneity, and temporal instability that qualifies SUNBOX as an AAA-Class solar simulator. At the end of this section, some characterizations made with SUNBOX are shown, using different functionalities, to obtain key parameters in different types of solar cells. The characterization methods that were used, such as I-V curves or spectroscopy impedance are also explained along the document. Finally, in the third section, other approaches to improve the efficiency of the devices were studied, based on the optical treatment of light (light management). This management lies on the ability that some materials have to interact with the incident light, mainly in the form of nanoparticles, nanorods, or small gratings. Using a Finite Element Method simulation software (COMSOL® and JCMSuite®), several results were obtained remarking the importance of the inclusion of a nanostructure inside a device, increasing the amount of photogenerated current by 40% in a hydrogenated amorphous silicon-based device and by 20.5% in a perovskite/silicon tandem solar cell. Furthermore, preliminary results were obtained applying a nanostructure into a deep ultraviolet light emitting diode, that went from a light extraction efficiency value of 4.57% to around 15%, thus, multiplying by three the amount of extracted light with the same electrical power consumption. In summary, the main conclusion of this work is that it is possible to increase the efficiency of actual devices by and important factor and that there is a lot of room for future improvements. A boost in efficiency can be applied not only using novel materials with better electrical and optical properties, but also optimizing the devices that exist nowadays using light management techniques through the inclusion of nanostructures inside these devices. This has been demonstrated during this work using both approaches: the material science, creating a novel material with a cutting-edge fabrication method, unraveling the properties and applications for this material; and the photonics science, simulating the response of the device with the inclusion of a nanostructure in it, showing an outstanding improvement in all three study cases.El mundo actual está constantemente sometido a cambios tecnológicos, y lo que en un momento pudo ser un gran avance para la vida en la Tierra, puede ocasionar efectos desastrosos en el futuro. Esto ha ocurrido en varias ocasiones en la historia de la humanidad y claros ejemplos de ello son el cambio climático, el calentamiento global y el incremento del efecto invernadero. Desde la Revolución Industrial se han producido diversos cambios y avances tecnológicos muy importantes para la sociedad: algunos de ellos nos permitieron avanzar como civilización, pero otros nos dirigen hacia nuestra propia autodestrucción. Un ejemplo reciente podría ser la emisión de los llamados clorofluorocarbonos a la atmósfera, unos gases que destruyeron la mayor parte de la capa de ozono en los polos de la Tierra, ocasionando que una gran parte de radiación solar incidiera en los glaciares polares, incrementando la fusión de ellos y con ello contribuyendo al peligroso deshielo polar. Hoy en día, uno de los grandes problemas a los que nos enfrentamos es la gran cantidad de dióxido de carbono que estamos vertiendo a la atmósfera, principalmente debido a las actividades de generación de energía. Por ello, el objetivo de esta tesis está centrado en incrementar la eficiencia de los dispositivos capaces de producir energía de una forma más limpia, usando la energía solar. De esta forma, en el futuro cercano seremos capaces de sustituir las fuentes de energía contaminantes que usamos actualmente por otras fuentes de energía mas limpia, renovables y que no emitan gases. Cierto es que este tema puede parecer prácticamente inabarcable, y por ello se ha dividido este trabajo en tres secciones principales que se estudian en detalle, para dar cobertura completa a todo el tema. La primera sección está basada en el estudio de las unidades básicas de la recolección de energía solar, las celdas solares. La tecnología más madura comercialmente disponible es la celda solar basada en silicio (tanto monocristalino como policristalino), pero durante los últimos años se han desarrollado otras tecnologías tales como las celdas orgánicas o de perovskita. Cada una de estas tecnologías tiene su propio procedimiento de fabricación, siendo las basadas en silicio las más caras de hacer debido a su procesamiento y a la gran cantidad de energía necesaria para su refinado. Sin embargo, en el caso de las celdas orgánicas y de perovskita los métodos de fabricación están basados en solventes y deposiciones de líquido en capas delgadas, lo que las hace mucho más económicas en términos de materiales y de consumo energético. Después de una breve explicación de las técnicas de deposición de lámina delgada más usadas (aplicables tanto en orgánicas como en perovskitas), se explica el proceso de fabricación paso a paso de una celda solar de yoduro de metilamonio plomo. Esta fabricación dio como resultado una celda solar con un valor de eficiencia del 16.9%. Debido a los problemas ambientales que puede causar este material (ya que contiene plomo, altamente tóxico), durante este trabajo se estudió también una perovskita libre de plomo (yoduro de estaño cesio). La conclusión principal extraída de este estudio es que esta perovskita libre de plomo puede tener aplicaciones muy interesantes, tales como ventanas inteligentes debido a su transparencia, pero sus problemas de conductividad eléctrica deben de ser resueltos en primer lugar, para conseguir un dispositivo eficiente. Para finalizar esta sección, se llevó a cabo una prueba de concepto que consistió en introducir fotodetectores orgánicos y de perovskita en un sistema de comunicación por luz visible (VLC), comprobando que ambas tecnologías respondían de forma correcta para formar parte de un sistema de transmisión de audio (su ancho de banda era superior a 40 kHz en ambos casos). Una vez se dispone de un dispositivo funcional, para poder determinar sus propiedades internas, se debe caracterizar. En esto consiste la segunda sección. Estas caracterizaciones deben hacerse siguiendo los estándares correspondientes, bajo ciertas condiciones y en unas circunstancias determinadas. Una de estas condiciones es tener una fuente de luz estable y bien definida, que pueda recrear el espectro AM1.5G (que es el espectro de luz que llega a la superficie de la Tierra emitido por el Sol) para excitar las muestras que se encuentren bajo análisis. Todas las restricciones y parámetros que determinan si una fuente de luz es adecuada o no para este proceso están definidos por la Comisión Electrotécnica Internacional bajo el estándar IEC 60904-9. Durante el desarrollo de esta tesis, debido a la necesidad de caracterizar dispositivos, se optó por crear una de estas fuentes de luz. Así nació SUNBOX, nuestro simulador solar. SUNBOX pertenece a la clase AAA según el estándar IEC, lo que significa que posee la mayor calidad posible como simulador solar. Está completamente basado en diodos emisores de luz y también es personalizable, con un espectro ajustable que puede cubrir desde 0.2 hasta 1.2 soles. Dispone de 14 longitudes de onda de emisión diferentes que también pueden ser ajustadas libremente, de forma que se pueden realizar análisis en longitudes de onda concretas, tales como azul, ultravioleta o infrarrojo. Es fácilmente distinguible de sus contrapartes comerciales disponibles en el mercado, ya que su chasis está realizado por impresión 3D, así que es muy ligero y de bajo coste. Debido a la protección de la propiedad intelectual bajo un modelo de utilidad y un registro software, solo una parte del diseño electrónico se explica en este documento, junto con todo el procedimiento de calibración que se llevó a cabo en términos de coincidencia espectral, homogeneidad y estabilidad temporal, que clasifican a SUNBOX como un simulador solar de clase AAA. Al final de esta sección, se muestran algunas de las caracterizaciones de dispositivos llevadas a cabo con SUNBOX, usando sus diferentes funcionalidades para obtener parámetros clave de distintos tipos de celdas solares. Los métodos de caracterización llevados a cabo, tales como el trazado de curvas tensión corriente o la espectroscopía de impedancias también se explican en el documento. Por último, en la tercera sección, se estudian otras técnicas para mejorar la eficiencia de los dispositivos, basadas en el tratamiento óptico de la luz (gestión de la luz o “light management”). Esta gestión de la luz se basa en la habilidad que tienen algunos materiales para interactuar con la luz que incide sobre ellos. Normalmente estos materiales necesitan estar en forma de nanopartículas, nanobarras o pequeñas redes de difracción. Usando varios softwares de simulación (COMSOL® y JCMSuite®) basados en el método de elementos finitos (FEM), se han obtenido varios resultados que remarcan la importancia de incluir nanoestructuras dentro de los dispositivos, incrementando la cantidad de corriente fotogenerada en un 40% en un dispositivo basado en silicio amorfo hidrogenado y en un 20.5% en un dispositivo basado en un tándem de perovskita y silicio monocristalino. Además, se han obtenido resultados preliminares que demuestran que estas nanoestructuras pueden ser también muy efectivas no solo en dispositivos receptores de luz, sino también en emisores. En este caso se aplicó una nanoestructura a un diodo emisor de luz ultravioleta profunda, que mejoró su eficiencia de extracción de luz de un 4.57% a alrededor de un 15%, triplicando la cantidad de luz emitida con el mismo consumo de potencia eléctrica. En resumen, la conclusión principal de este trabajo es que es posible incrementar la eficiencia de los dispositivos actuales de una forma sustancial, quedando aún mucho espacio para mejorar. Se ha demostrado que un incremento en la eficiencia puede obtenerse no solo usando materiales novedosos con mejores propiedades ópticas y eléctricas, sino también optimizando los dispositivos existentes actualmente usando técnicas de gestión de la luz a través de la inclusión de nanoestructuras en estos dispositivos. Respecto a la primera aproximación, relacionada con la ciencia de materiales, en este trabajo se ha fabricado un material novedoso usando una técnica de fabricación poco explorada en estas aplicaciones (co-evaporación), descubriendo las propiedades y posibles aplicaciones de este material. Respecto a la segunda aproximación, relacionada con la fotónica, se han creado diseños de nanoestructuras y se ha simulado su respuesta, descubriendo una mejora muy importante en la eficiencia de los tres dispositivos estudiados.The present work has been funded from the following projects: • Comunidad de Madrid through SINFOTON-CM Research Program (S2013/MIT-2790) and SINFOTON2-CM (S2018/NMT-4326) • Ministerio de Economia, Agencia Estatal de Investigación and European Union’s FEDER through TEC2016-77242-C3-(1-R, 2-R and 3-R) AEI/FEDER, UE Projects. • European Research Council (ERC) via Consolidator Grant (724424-No-LIMIT) • Generalitat Valenciana via Prometeo Grant Q-Devices (Prometeo/2018/098) • European Commission via FET Open grant (862656-DROP-IT) Also, this project could not be possible with the financial support of the Ministerio de Educación y Formación Profesional through the following grants that I have received: • Doctoral Grant FPU research fellowship (FPU17/00612). • Research Stay Grant (EST18/00399) supporting my research stay at Jaume I University (Castellón, Spain) • Research Stay Grant (EST19/00073) supporting my research stay at Helmholtz Zentrum Berlin and Zuse Institute Berlin (Berlin, Germany).Programa de Doctorado en Ingeniería Eléctrica, Electrónica y Automática por la Universidad Carlos III de MadridPresidente: Javier Alda Serrano.- Secretario: Fernando B. Naranjo Vega.- Vocal: Sven Burge

Optical characterization of lead-free Cs2SnI6 double Perovskite Fabricated from degraded and reconstructed CsSnI3 films

Halide perovskites have experienced a huge development in the past years, but they still have two major challenges for their massive implantation: the long-term stability and the use of lead. One of the most obvious lead-free candidates to replace these perovskites is CsSnI3, but due to its poor environmental stability, it has been discarded for the fabrication of stable devices. Nevertheless, ambient degradation of CsSnI3 and ulterior reconstruction produce a relatively stable lead-free Cs2SnI6 double perovskite with interesting optical properties that have not been deeply characterized previously. In this work, the potential use for the optical properties of Cs2SnI6 is studied and compared with that of the most common halide perovskite, CH3NH3PbI3 (MAPbI3). The Cs2SnI6 films stayed in a standard atmosphere for a week without showing any signs of degradation. They also demonstrated better reflective behavior than MAPbI3 and higher absorption in the 650 and 730 nm spectral range, making this material interesting for the development of photodetectors in this region. This study demonstrates that Cs2SnI6 is a promising material for photodevices, as it highlights its main characteristics and optical parameters, giving an original view on the use of the double perovskite, but at the same time emphasizing the need to improve the electrical properties for the development of efficient optoelectronic devices.E.L.-F. wants to express his gratitude to the Ministerio de Educación y Formación Profesional for his doctoral grant (FPU research fellowship FPU17/00612) and his research stay grant (EST18/00399). This work was partially supported by the European Research Council (ERC) via Consolidator Grant (724424-No-LIMIT) and the European Commission via FET Open Grant (862656 - DROP-IT). We acknowledge SCIC from Jaume I University (UJI) for help with XRD and SEM-EDS characterization

A low-cost LED-Based solar simulator

Solar simulators are a fundamental instrument to characterize solar cells parameters, as they can reproduce the operating conditions under which the solar cells are going to work. However, these systems are frequently big, heavy, and expensive, and a small solar simulator could be a good contribution to test small prototyping devices manufactured in research labs, especially if it could manage the irradiation at any wavelength interval in a custom way. We have designed, developed, and calibrated a small solar simulator made entirely with LEDs, no optics inside, and electronically controlled through a PC using an Arduino microcontroller. The whole structure is 3-D printed in black PLA plastic. The electrical current through the LEDs, and thus the spectral irradiance of the simulator, is controlled with a very intuitive LabVIEW interface. As our calibration proves, we have built an easily reproducible and low-cost Class AAA solar simulator in a central illumination area of 1 cm 2 , according to the IEC60904-9 standard. This means that the homogeneity in that area is under a 2% deviation in spatial terms, below 0.5% in temporal terms, and is a factor of a 3% close to the AM1.5G sun reference spectrum. The system can be built and used in any research lab to get quick tests of new small solar cells of any material.This work was supported in part by the Spanish Ministerio de Economía y Competitividad through AEI/FEDER, UE Funds under Grant TEC2016-77242-C3-1-R and in part by the Comunidad de Madrid SINFOTON-CM Research Program under Grant S2013/MIT-2790. The work of E. López-Fraguas was supported by the Ministerio de Educación y Formación Profesional for his Doctoral Grant through FPU Research Fellowship under Grant FPU17/00612

Efficient light management in a monolithic tandem perovskite /silicon solar cell by using a hybrid metasurface

Solar energy is now dealing with the challenge of overcoming the Shockley&-Queisser limit of single bandgap solar cells. Multilayer solar cells are a promising solution as the so-called third generation of solar cells. The combination of materials with different bandgap energies in multijunction cells enables power conversion efficiencies up to 30% at reasonable costs. However, interfaces between different layers are critical due to optical losses. In this work, we propose a hybrid metasurface in a monolithic perovskite-silicon solar cell. The design takes advantage of light management to optimize the absorption in the perovskite, as well as an efficient light guiding towards the silicon subcell. Furthermore, we have also included the effect of a textured back contact. The optimum proposal provides an enhancement of the matched short-circuit current density of a 20.5% respect to the used planar reference.This research was funded by Ministerio de Economía y Competitividad, grant number TEC2016-77242-C3-1-R Grant (AEI/FEDER, UE funds), and Comunidad de Madrid and FEDER program through the SINFOTON-CM Research (grant number S2013/MIT-2790) and SINFOTON2-CM (granT number S2018/NMT-4326) programs

Boosting ultrathin aSi-H solar cells absorption through a nanoparticle cross-packed metasurface

Hydrogenated amorphous silicon (a-Si:H) solar cells have some performance limitations related to the mobility and lifetime of their carriers. For this reason, it is interesting to explore thin-film solutions, achieving a tradeoff between photons optical absorption and the electrical path of the carriers to get the optimum thickness. In this work, we propose the insertion of a metasurface based on a cross-patterned ITO contact film, where the crosses are filled with nanospheres. We numerically demonstrate that this configuration improves the photogenerated current up to a 40% by means of the resonant effects produced by the metasurface, being independent on the impinging light polarization. Light handling mechanisms guide light into the active and auxiliary layers, increasing the effective absorption and mitigating the Staebler-Wronski effect. The selection of optimum materials and parameters results in nanospheres of ZnO with a 220 nm radius.This work was supported by the Ministerio de Economía y Competitividad of Spain (TEC2016-77242-C3-1-R Grant, AEI/FEDER, European Union funds). López-Fraguas thanks funding support from Ministerio de Educación y Formación Profesional of Spain for his doctoral grant (FPU research fellowship Ref. FPU17/00612). The authors acknowledge Prof. Joshua M. Pearce for providing them with experimental n and k values of the optical constants of the aSi-H

A monolithic nanostructured-perovskite/silicon tandem solar cell: feasibility of light management through geometry and materials selection

The use of several layers of different materials, taking advantage of their complementary bandgap energies, improves the absorption in multi-junction solar cells. Unfortunately, the inherent efficiency increment of this strategy has a limitation: each interface introduces optical losses. In this paper, we study the effects of materials and geometry in the optical performance of a nanostructured hybrid perovskite - silicon tandem solar cell. Our proposed design increases the performance of both subcells by managing light towards the active layer, as well as by minimizing reflections losses in the interfaces. We sweep both refractive index and thickness of the transport layers and the dielectric spacer composing the metasurface, obtaining a range of these parameters for the proper operation of the device. Using these values, we obtain a reduction in the optical losses, in particular they are more than a 33% lower than those of a planar cell, mainly due to a reduction of the reflectivity in the device. This approach leads to an enhancement in the optical response, widens the possibilities for the manufacturers to use different materials, and allows wide geometrical tolerances.E.L.F. wants to express his gratitude to the Ministerio de Educación y Formación Profesional for his doctoral grant (FPU research fellowship Ref. FPU17/00612). F.A.C. wants to express his gratitude to the Comunidad de Madrid and UE through Y.E.I. program for his financial support (Y.E.I.) (Ref. PEJD-2018-PRE/IND-9348). The authors acknowledge the financial support of the Ministerio de Economía y Competitividad for the TEC2016-77242-C3-1-R Grant (AEI/FEDER, UE funds). This work was also supported by Comunidad de Madrid and FSE/FEDER Program under grants SINFOTON2-CM (S2018/NMT-4326) and TEFLON-CM (Y2018/EMT-4892)

Chemi-Structural Stabilization of Formamidinium Lead Iodide Perovskite by Using Embedded Quantum Dots

The approaches to stabilize the perovskite structure of formamidinium lead iodide (FAPI) commonly result in a blue shift of the band gap, which limits the maximum photoconversion efficiency. Here, we report the use of PbS colloidal quantum dots (QDs) as a stabilizing agent, preserving the original low band gap of 1.5 eV. The surface chemistry of PbS plays a pivotal role by developing strong bonds with the black phase but weak ones with the yellow phase. As a result, a stable perovskite FAPI black phase can be formed at temperatures as low as 85 °C in just 10 min, setting a record of concomitantly fast and low-temperature formation for FAPI, with important consequences for industrialization. FAPI thin films obtained through this procedure reach an open-circuit potential (Voc) of 1.105 V, 91% of the maximum theoretical Voc, and preserve the efficiency for more than 700 h. These findings reveal the potential of strategies exploiting the chemi-structural properties of external additives to relax the tolerance factor and optimize the optoelectronic performance of perovskite materials

Identification of Degradation Mechanisms in Slot-Die-Coated Nonfullerene ITO-Free Organic Solar Cells Using Different Illumination Spectra

In this work, we have studied degradation mechanisms of nonfullerene-based organic solar cells with PET/Ag/ZnO/PBDTB-T:ITIC/PEDOT:PSS/CPP PEDOT:PSS device structure. We compare pristine and degraded samples that were subjected to outdoor degradation following the standard ISOS-O2 protocol. The ideality factors for different incident wavelengths obtained from open-circuit voltage vs irradiation level and current density–voltage (J–V) measurements at different temperatures indicate that for aged samples recombination is governed by the Shockley–Read–Hall mechanism occurring in a region near the anode. Samples were also characterized using impedance spectroscopy (IS) and fitted to an electrical model. Impedance parameters were used to obtain mobility, indicating a clear degradation of the active layer blend for aged samples. The change in the chemical capacitance also reveals a worsening in carrier extraction. Finally, two-dimensional (2D) numerical simulations and fits to experimental J–V curves confirm the existence of a layer near the anode contact with poorer mobility and a decrease in the anode work function (WF) for the degraded samples.This work was supported by Comunidad de Madrid under the SINFOTON2-CM Research Program (S2018/NMT-4326-SINFOTON2-CM) and the Spanish Ministry of Economy, the Agencia Estatal de Investigación, and European Union's FEDER under the TEC2016−77242-C1/C2/C3 AEI/FEDER, UE Projects. The work of E.L.-F. was supported by the Ministerio de Educación y Formación Profesional for his Doctoral Grant through the FPU Research Fellowship under Grant FPU17/00612. M.M., J.L., E.D., and V.T. acknowledge that part of this work was developed within the RollFlex project, part-financed by Interreg Deutschland-Danmark with means from the European Regional Development Fund and the Southern Denmark Growth Forum. M.M. and V.T. acknowledge the support from the Villum Foundation for Project CompliantPV (Grant No. 13365). Finally, all authors acknowledge the support from the EU Framework Program Horizon 2020 for MNPS COST ACTION MP1307 StableNextSol.Publicad

An All-Organic Flexible Visible Light Communication System

Visible light communication systems can be used in a wide variety of applications, from driving to home automation. The use of wearables can increase the potential applications in indoor systems to send and receive specific and customized information. We have designed and developed a fully organic and flexible Visible Light Communication system using a flexible OLED, a flexible P3HT:PCBM-based organic photodiode (OPD) and flexible PCBs for the emitter and receiver conditioning circuits. We have fabricated and characterized the I-V curve, modulation response and impedance of the flexible OPD. As emitter we have used a commercial flexible organic luminaire with dimensions 99 × 99 × 0.88 mm, and we have characterized its modulation response. All the devices show frequency responses that allow operation over 40 kHz, thus enabling the transmission of high quality audio. Finally, we integrated the emitter and receiver components and its electronic drivers, to build an all-organic flexible VLC system capable of transmitting an audio file in real-time, as a proof of concept of the indoor capabilities of such a system.This Project was funded by Comunidad de Madrid through the SINFOTON-CM Research Program (S2013/MIT-2790), and the Spanish Ministry of Economy, the Agencia Estatal de Investigación and European Union's FEDER through the TEC2016-77242-C3-(1-R, 2-R and 3-R) AEI/FEDER, UE Projects

GEODIVULGAR: Geología y Sociedad

Fac. de Ciencias GeológicasFALSEsubmitte