PI: Mariano Campoy
Following promising early breakthroughs, progress in the development of high-performance multicomponent organic energy materials has stalled due to a bottleneck in device optimization. FOREMAT will develop a breakthrough technology to overcome this bottleneck by shifting from fabrication-intense to measurement-intense assessment methods, enabling rapid multi-parameter optimization of novel systems. Our goal is to deliver organic material systems with a step-change in performance, bringing them close to the expected market turn point, including panchromatic organic photovoltaics with ca 15% efficiencies and thermoelectric devices that could revolutionize waste heat recovery by their flexibility, lightweight and high power factor. The development of multicomponent materials promises to dramatically improve the cost, efficiency and stability of organic energy devices. For example, they allow to engineer broad-band absorption in photovoltaics matched to the sun’s spectrum, or to create composites that conduct electricity like metals while thermally insulate like cotton yielding thermoelectric devices beyond the state-of-the-art.
Despite these advantages, the long time required to evaluate promising organic multinaries currently limits their development. We will circumvent this problem by developing a high-throughput technology that will allow evaluation times up to two orders of magnitude faster saving, at the same time, around 90% of material. To meet these ambitious goals, we will advance novel fabrication tools and create samples bearing a high density of information arising from 2-dimensional gradual variations in relevant parameters that will be sequentially tested with increasing resolution in order to determine optimum values with high precision. This quantitative step will enable a disruptive qualitative change as in depth multidimensional studies will lead to design rationales for multicomponent systems with step-change performance in energy applications.
More information about FOREMAT
- Additional explanation for the case of high throughput evaluation of materials for photovoltaics can be found in the following press realease (Spanish)
and in the following 9 minutes video (English)
- Video of the full explanation of fabrication of organic solar cells with thickness gradients
PI: Agustín Mihi
The use of these structures within actual devices will be most beneficial for enhanced light absorption in thin solar cells, photodetectors and to develop new sensors and light emitters. However, emerging optoelectronic devices rely on large area and low cost fabrication routes such as roll to roll or solution processing, to cut manufacturing costs and increase the production throughput. If the exciting properties exhibited by the photonic structures are to be implemented in these devices, then they too have to be processed in a similar fashion as the devices they intend to improve. This research line is aimed to develop photonic electrodes that will enhance light matter interaction based on wave optics phenomena while being fabricated with techniques fully compatible with today’s mass production approaches, allowing seamless integration of wave optics components in current devices.
The aim of the project RAINBOW, co-directed by Prof. A.R. Goñi and Dr. M. Campoy-Quiles, is to advance a solar technology that is simultaneously cost-effective and highly efficient. The strategy consists in developing solar energy harvesting devices based on the principle of splitting the solar spectrum into several components, each of which will be absorbed by a solar device with maximum external quantum efficiency (EQE) for the corresponding spectral range. For that purpose, we propose to structure the active layer of the device so to exhibit a lateral gradient in its band gap or a series of adjacent cells with varying band gap, by processing the materials from solution. In this way, energy relaxation losses due to carrier thermalization will be minimized. We thus expect the device to be able to overcome the Shockley-Queisser limit for a single junction, leading to higher conversion efficiencies as compared to conventional solar cells of the same area. We choose devices based on conjugated polymer blends or hybrid lead halide perovskites as we expect then to perform well in a spectral splitting design while being readily processable through low cost methods. A peculiarity of our rainbow design is that the infrared (IR) part of the solar spectrum (1 to 2.5 microns) would be collected by either a solar thermoelectric generator or a plasmon-resonance, cold-cathode thermionic emitter, which would further contribute to enhance power conversion efficiency. The final goal is to obtain a demonstrator of a spectral beam-splitting, rainbow hybrid device with substantially improved solar energy conversion efficiency exploiting the full solar spectrum from the IR up to the ultraviolet spectral range. Therefore, our rainbow approach will yield solar energy harvesters which outperform conventional tandem solar cells in two key points: The overall conversion efficiency improves substantially through harvesting of the IR part of the solar spectrum and including a large number of subcells, and the device fabrication is low cost and technologically uncomplicated.
In the framework of the Marie Sklodowska-Curie Action, call H2020-MSCA-IF-2018, Dr. Luis. A. Pérez was awarded with an Individual Fellowship aiming at advancing sustainable energy production by developing a new class of photovoltaic/thermoelectric (PV/TE) hybrid devices that outperform both the solar cell and the thermoelectric generator working separately. The key concept of Plasmionico is the incorporation of a “cold-cathode” thermionic generator as TE component. In contrast to conventional thermionic generators, where the cathode is brought to extremely high temperatures, in the cold-cathode case, the emission of electrons proceeds from the absorption of infrared (IR) photons in the unused region of the solar spectrum below the PV cell bandgap. The IR photons will launch plasmons at a nanostructured metallic cathode, generating a photocurrent. Apart from its higher efficiency, a great advantage of the thermionic electron emission by photo-excitation of plasmonic resonances is that is not restricted to a particular class of materials, working for Si-based electronic devices as well as for organic (soft and flexible) and/or hybrid perovskite materials, since the cathode temperature is that of a working solar cell. The research activities within this project will span the whole added-value chain from fundamental studies of materials and their adequacy for thermionic generation, including the design and optimization of the plasmonic nanostructures, reaching higher technological readiness levels by implementation of materials and concepts into a proof-of-concept hybrid PV/TE-device.
Agustin Mihi, M. Isabel Alonso
Surface Enhanced Raman Scattering (SERS) has been a widely exploited technique in the last years. As a versatile and established technique, it addresses both fundamental scientific questions and practical problems. These applied areas are mostly related to sensing of trace substances in many different fields. There are however, several challenges still to be addressed to develop the full potential of SERS in areas such as biosensing. Solid state SERS devices are particularly interesting for the development of portable devices in which the most critical component is the plasmonic substrate. This research plan aims at the design and fabrication of metallic substrates for SERS based in plasmonic crystals operating at several excitation wavelengths, specially towards the NIR region, while maintaing a low cost and high reproducibility.
PI: Alejandro Goñi
All members of the group are involved in nanoTHERM bringing together expertise including fundamental Solid State Physics, light-matter interactions and study of electrons and phonons in nanostructures to work towards more efficient thermoelectric materials with good electrical and phonon-blocking, low thermal conductivities. Tailoring electronic and phononic properties of nanomaterials: towards ideal thermoelectricity is a CONSOLIDER research program that runs from 2010 to 2015. It aims at producing a considerable breakthrough in the understanding of the fundamental physics underlying thermoelectricity to produce next-generation thermoelectric materials and devices. Nine groups form the core of an interdisciplinary community covering from theory to experiment and technology to achieve validation of the materials in terms of their suitability for end-users. The group at ICMAB coordinates the work package devoted to synthesis of nanostructured inorganic and hybrid materials, and is mainly developing the design and fabrication of inorganic semiconductor-based nanostructures such as superlattices (SLs), nanowires (NWs) and quantum dots (QDs) with the explicit purpose of exploiting the reduced dimensionality to enhance TE power. The SiGe nanostructures fabricated using Molecular Beam Epitaxy are compatible with all-Si technology, thus enabling monolithic integration with established Si processing, for example as on-chip coolers. Their study is also expected to lead to deep insights about the currently rather limited understanding of the flow heat control and the effect of dimensionality on the heat transport in SiGe and other superlattice structures. The group is also focused on the preparation of new generations of organic thermoelectric materials for evidencing the critical phenomena and the relation structure/properties which allow enhancing the thermoelectric figure-of-merit ZT. Extensive studies of the influence of doping, synthesis routes and chemical composition of soft matter on the properties of charges, phonon transport and on the intrinsic properties of the polymers will be carried out. The group will also dedicate efforts to hybrid structures of engineered organic-inorganic materials, such as colloidal semiconductor QDs in polymeric matrices.
PI: Mariano Campoy
TranspEnergy is framed within a long standing collaboration with the department of ‘Functional Printing & Embedded Devices’ of the technological center Eurecat. Our main goal is to manufacture semitransparent organic photovoltaic modules by roll-to-roll coating techniques with a desired/targeted color range: photovoltaics “a la carte”.
To meet this goal, TranspEnergy includes both optical computer modelling and lab/fab-scale studies. Computational simulations will allow predicting solar devices color and transparency meanwhile lab-scale work let us check both the validity as well as try cost-effectively new materials and device configurations. Finally, the last step is scaling-up, which consists of transfer the know-how from lab-scale to fab-scale.
Lab-scale studies will focus on testing several materials and device configurations saving time and resources. Characterization techniques used to evaluate the performance of the devices include LBIC and Raman. LBIC (Laser Beam Induced Current) is used to create a photocurrent map. This technique is a very valuable tool complementing non-localized measurements of the JV-curve. As well, Raman Spectroscopy measurement is used to create a composition mapping. With the perfect matching of this two characterization techniques we can identify defects and materials contribution.
On the other hand, optical simulations based on transfer matrix method predict transparency, color and electrical properties. As input parameters, optical simulations are based on spectroscopy ellipsometry data to experimentally determine optical properties of the device. Furthermore, this method allows to evaluate multi-components blends, which is very valuable to analyze color and transparency sensitivity. Finally, the reverse problem i.e. finding the appropriate material and device geometry that results in a desired color, will also be studied.
The final aim of this project is to develop active architectonic elements being aesthetic and colored easily integrated in buildings. OPV technology has unique features such as ease of color tunability and transparency, which could be a perfect technology to transform passive windows or skylights for active light-harvesting elements.
KEYWORDS: OPV (Organic photovoltaics), BIPV (Building integrated photovoltaics), color tuning, R2R (roll-to-roll)
EXPLOTHRA is an ambitious project which aims to create a breakthrough in our understanding and ability to control heat transport at the nanoscale. Its main objective is to study thermal transport in the temporal and spatial domains simultaneously. This will provide invaluable information on the nature of heat in different material systems and it will be the key to open novel research fronts. We aim to understand to what extent we can manipulate heat propagation, and explore the potential of heat as exploitable quantity for novel applications in the fields of energy and electronics. The specific question that this project aims to answer is how heat propagates at the nanoscale and on short time scales, i.e., in non-equilibrium conditions. The key objective of the project is to visualize the propagation of heat in extreme slow motion in technologically relevant systems. We will develop an original methodology based on probing time-resolved optical reflectance through an interferometric approach which will provide large sensing capabilities. We will test the technique through standard systems in 1D, 2D and 3D thermal flow geometries. We expect that this technique will become a state of the art technique in nanoscale thermal transport.
TANGENTS is an ambitious project which aims to create a breakthrough in our understanding and ability to control heat transport and temperature sensing at the nanoscale. Its main objective is to study thermal transport with sub-30 nm thermal-spatial resolution and with temperature accuracies below 50 mK. We aim to understand to what extent we can manipulate heat propagation, and explore the potential of heat as exploitable quantity for novel applications in the fields of energy and electronics. The specific question that this project aims to answer is how heat propagates at the nanoscale where the heat transport regime exhibits the transition from ballistic to diffusive. The key objective of the project is to visualize the propagation of heat in spatial scales smaller than the thermal phonon mean free path in technologically relevant systems. The ambitious ultimate purpose of this project is to extend the experimental methodology to the time- domain in order to probe real-time heat propagation with nanoscale resolution.
The mission of the SEPOMO – Spins in Efficient Photovoltaic devices based on Organic MOlecules – is to bring the performance of OSCs forward by taking advantage of the so far unexplored degree of freedom of photogenerated species in organic materials, their spin.
This challenging idea provides a unified platform for the excellent research to promote the world-wide position of Europe in the field of organic photovoltaics and electronics, and to train strongly motivated early stage researchers for a career in science and technology oriented industry that is rapidly growing.
The project SENSORAÏM, aims to improve quality, efficiency and sustainability in viticulture by providing key data in real time across the whole vineyard, with autonomous sensors based on organic thermoelectric generator technology.
In a first step, temperature and humidity will be monitored by installing a network of distributed autonomous wireless sensors that communicate with a central server, and from there with the cloud and an application on the mobile phone of the winegrower. These data will help to prevent the effects of frost and drought, as well as to fine-tune the drop on demand watering of plants at the different regions of the vineyard, and obtain data to help preventing plagues. In a second phase, other parameters might be monitored, such as ground pH or nutrients as relevant parameters that will enable the implementation of real-time smart irrigation systems.
The power autonomy of the sensor is achieved thanks to our unique generators. Throughout the past three years, we have developed a patented organic thermoelectric generator technology, a device that uses small temperature differences in the environment to generate enough power to supply simple sensors. Compared to traditionally used batteries, our solution is more environmentally friendly as it does not involve toxic elements, while also being cheaper in the long run, since our generators do not require maintenance.
Finished projects
Most members of the group are involved in PHOTOCOMB: Understanding and optimizing nanostructured organic photovoltaics through a processing scheme inspired by combinatorial analysis. This research program runs from 2013 to 2015 and it aims at developing processing schemes that enable the fabrication of organic photovoltaic (OPV) active layers with a controlled graded structure across its area in order to optimize device performance in an effective and speedy manner, as well as to allow fundamental studies on model samples. Inspired by the concept of combinatorial screening, we are studying samples showing continuous variations in one or two parameters, rather than using sets of discrete samples. The gradients span the following main parameters: degree of order, molecular orientation, composition and film thickness. We are implementing experimental setups to perform mapping characterization, in this way, the multiparameter space of the samples is systematically investigated to reveal the most relevant combination governing the performance of organic photovoltaics. During the project we will develop a characterization setup based on optimization for maximum photovoltaic efficiency by implementing an XYZ mapping stage with micrometer precision and a solar simulator to carry out photocurrent maps. We intend to demonstrate the different principles in the widely studied material system, polythiophene (P3HT) mixed with soluble derivative fullerene (PCBM) and then extend it to other systems with higher efficiencies. At the same time, establishing this interplay between fundamental knowledge and performance may help to identify spectroscopic probes that can be used to asses film quality during cell fabrication for in-situ monitoring at industrial level. Non-invasive methods such as ellipsometry and Raman show great potential for this, and the group has many years of experience on its application.
Alejandro Goñi, Mariano Campoy
Amongst the different alternatives for renewable energy production, photovoltaic (PV) and thermoelectric (TE) technologies are being increasingly considered to play a significant role in the future energy mix. This is specially so for small and medium-scale energy generation/harvesting and, particularly, for standalone applications. Furthermore, as in many aspects of nature, synergic properties and/or enhanced performances emerge when combining different but complementary materials into composites (e.g. hybrid materials). The aim of this proposal is twofold: Advance novel hybrid materials and develop hybrid photovoltaic/thermoelectric applications.