Visible and near-infrared organic photosensitizers comprising isoindigo derivatives as chromophores: synthesis, optoelectronic properties and factors limiting their efficiency in dye solar cells

The development of ruthenium-free organic photosensitizers showing panchromatic absorption up to the near-infrared (NIR) region for application in dye-sensitized solar cells (DSSCs) is still scarce. Among the sensitizers with absorption beyond 700 nm and developed for DSSCs, only zinc-phthalocyanine and boron-dibenzopyrromethene-based dyes have been able to reach efficiencies as high as 6%. Here we report metal-free organic dyes based on isoindigo, thieno-isoindigo or benzo-thieno-isoindigo chromophores that absorb in the UV-visible and NIR spectral range up to 900 nm. These molecules, that exhibit purple, blue, or green hues, were used to sensitize TiO2 mesoporous electrodes in order to fabricate DSSCs with an iodide/triiodide-based electrolyte. Advanced photophysical characterizations, including charge extraction, transient photovoltage, and laser transient absorption spectroscopy experiments, combined with density functional theory modeling and computational investigations allow us to fully unravel the interfacial processes at the origin of the solar cell performances and to identify the limiting factors. A power conversion efficiency as high as 7% associated with a Jsc close to 19 mA cm−2 was obtained with one of the dyes, which is comparable to those of the best panchromatic organic dyes reported so far. We also demonstrate in this work that the Voc of the solar cells is linearly correlated to the dipolar moments of the oxidized dyes, the molecules possessing larger dipoles leading to the highest Voc value

Adaptive Reclosing Technique Using Variational Mode Decomposition Algorithm in BESS-Based Microgrid

This study introduces a novel adaptive technique to accelerate the process of reclosing in a Battery Energy Storage System (BESS)-based microgrid system to provide uninterrupted power supply (UPS). Two different methodologies, Fault Current Contribution Ratio (FCCR) and Variational Mode Decomposition (VMD) are used to implement the proposed technique. First, the FCCR between the healthy and faulty phases is estimated in the relay after the occurrence of the transient. In the next stage, exact fault occurrences and clearance instances are detected using the VMD technique. The exact detection of fault clearance time will help reduce the conventional outage time. This will reduce the unwanted burden on the BESS as it can be used adaptively during the fault only. The comparative assessment is done to show the efficacy of the proposed reclosing method. The proposed technique will also help distinguish faults from switching operations. The performance of the proposed method is validated through a modified IEEE 13-bus BESS-based microgrid architecture. The EMTDC/PSCAD software is used for simulation. The algorithms are developed on the MATLAB platform. Real-time test results are also provided for the signals obtained from the Smart Grid Technology Laboratory (SGTL) lab setup. The results prove the efficacy of the proposed technique

Minimization of Carrier Losses for Efficient Perovskite Solar Cells through Structural Modification of Triphenylamine Derivatives

Three hole transport materials (HTMs) based on a substituted triphenylamine moiety have been synthesized and successfully employed in triple-cation mixed-halide PSCs, reaching efficiencies of 19.4 %. The efficiencies, comparable to those obtained using spiro-OMeTAD, point them out as promising candidates for easily attainable and cost-effective alternatives for PSCs, given their facile synthesis from commercially available materials. Interestingly, although all these HTMs show similar chemical and physical properties, they provide different carrier recombination kinetics. Our results demonstrate that is feasible through the molecular design of the HTM to minimize carrier losses and, thus, increase the solar cell efficiencies

Visible and near-infrared organic photosensitizers comprising isoindigo derivatives as chromophores: synthesis, optoelectronic properties and factors limiting their efficiency in dye solar cells

The development of ruthenium-free organic photosensitizers showing panchromatic absorption up to the near-infrared (NIR) region for application in dye-sensitized solar cells (DSSCs) is still scarce. Among the sensitizers with absorption beyond 700 nm and developed for DSSCs, only zinc-phthalocyanine and boron-dibenzopyrromethene-based dyes have been able to reach efficiencies as high as 6%. Here we report metal-free organic dyes based on isoindigo, thieno-isoindigo or benzo-thieno-isoindigo chromophores that absorb in the UV-visible and NIR spectral range up to 900 nm. These molecules, that exhibit purple, blue, or green hues, were used to sensitize TiO2 mesoporous electrodes in order to fabricate DSSCs with an iodide/triiodide-based electrolyte. Advanced photophysical characterizations, including charge extraction, transient photovoltage, and laser transient absorption spectroscopy experiments, combined with density functional theory modeling and computational investigations allow us to fully unravel the interfacial processes at the origin of the solar cell performances and to identify the limiting factors. A power conversion efficiency as high as 7% associated with a Jsc close to 19 mA cm−2 was obtained with one of the dyes, which is comparable to those of the best panchromatic organic dyes reported so far. We also demonstrate in this work that the Voc of the solar cells is linearly correlated to the dipolar moments of the oxidized dyes, the molecules possessing larger dipoles leading to the highest Voc value

D-NA4.1 Functional Scenarios:WP5 Deliverable D5.1: D-NA4.1 Functional Scenarios

This deliverable describes the work conducted in ERIGrid 2.0 task NA4.1 ’Definition of Functional Scenarios’. The work has been conducted via a survey and a brainstorming workshop. The results are six Functional Scenarios: Ancillary services provided by Distributed Energy Resources (DERs) and active grid assets, Microgrids & energy communities, Sector coupling, Frequency and voltage stability in inverter dominated power systems, Aggregation and flexibility management, and Digitalisation, which describe the overarching topics within ERIGrid 2.0. The Functional Scenarios will be used as an input in further ERIGrid 2.0 work. Smart grid and smart energy systems solutions have become complex and multidisciplinary. With the further integration of Information and Communication Technology (ICT) and other energy systems new testing scenarios, profiles, and processes must be defined. In order to achieve this, big trends affecting research, testing, and validation processes have been reviewed, with a special focus on new aspects such as interoperability testing or digitalisation. The scenario descriptions define requirements, actors, etc. on a functional level. ERIGrid 2.0 work package NA4 ’Iterative Creation of Scenarios and Test Case Profiles’ addresses these needs. This work has been conducted with emphasis on the alignment with the European Green Deal, further support on the technology validation and roll-out phases, and further integration of the research infrastructures. A Functional Scenario has been defined as an umbrella term comprising of motivation and relevance for ERIGrid 2.0, system descriptions, use case and test case descriptions, and experimental setup descriptions. Each scenario has a single core idea and is formed on the basis of inclusiveness. Functional Scenarios consider several high-level scenarios in other projects and networks as a background forming the overall circumstances in which the Functional Scenario is considered. The high-level scenarios provide a holistic understanding of the current status and development while also highlighting future visions and requirements impacting the Functional Scenarios. The high-level scenarios also address the high-level drivers for the Functional Scenarios, such as needs for digitalisation of the smart energy systems. Furthermore, Functional Scenarios are related to the generic system configurations developed in ERIGrid and consider the work conducted in ERIGrid as a strong background for ERIGrid 2.0. The necessity for a mutual understanding of scenarios which are of interest to the ERIGrid 2.0 partners and their research infrastructures and in alignment of the project objectives, led to conducting a survey regarding the first actions of the NA4.1 work. The purpose of this survey was to gather inputs on a set of Functional Scenarios that were analysed in more detail to deduce the most relevant approaches for ERIGrid 2.0. Overall, 15 partners participated in the survey and submitted 35 scenarios. The survey results include scenarios on sector coupling, multi-energy systems, ICT and automation, energy communities, microgrids and low- inertia grids, and stability, control and grid code challenges. Detailed descriptions of Functional Scenarios submitted to the survey are presented in Appendix A: Functional Scenario Survey Data of this deliverable. The formation of the Functional Scenarios was organised in six working groups, each of which focused on a single Functional Scenario. The decision on the six Functional Scenario was taken during the NA4 regular meetings and the brainstorming workshop itself based on the results of the Functional Scenario survey. The focus of the first working group has been on a component focused scenario developed based on the survey results on DERs and inverters. The resulting Functional Scenario 1 integrates key components, such as DER inverters and controllers with ICT, control and automation architectures to enable new grid services with the development of interfaces between the active components. The second working group has been focused on topics related to microgrids and energy communities forming Functional Scenario 2 to support the local microgrid and energy community development by enabling flexibility services locally with ICT and control including exploitation of grid intelligence. While the third working group has been working on the survey results on sector coupling and multi-energy systems with Functional Scenario 3 anticipating a massive roll-out of power-to-X components in the near future by developing system level understanding of the impacts on the electrical domain. The fourth working group has been focused on grid management and overall the perspectives of Distribution System Operators (DSOs) and Transmission System Operators (TSOs) resulting in Functional Scenario 4 assuring frequency and voltage stability in low inertia systems through capabilities of Renewable Energy Sources (RES), Distributed Generation (DG), controllable loads and storage systems as well as ICT and control systems. The fifth working group has been based on the survey results comprising of aggregation, flexibility, market and reserve topics and defined Functional Scenario 5 to focus on communication functionality for aggregation, service matching, fail-over, configuration, and interoperability addressing scale-related properties of aggregation and control solutions. Lastly, the sixth working group has been focused on digitalisation including wide range of topics such as ICT infrastructure, communication, automation, control and monitoring. Functional Scenario 6 explores the impact of ICT solutions on the physical (electrical power) system covering new applications of data and data processing as well as new paths for exchanging data. The Functional Scenario templates used during the brainstorming workshop have been included in the Appendix B: Functional Scenario Templates. The work started in NA4.1 will continue in NA4.2 and NA4.4 with discussions on more detailed definitions of the test cases which will initially provide the inputs for other project activities. The discourse on the Functional Scenarios is also assumed to support ERIGrid 2.0 physical lab and virtual access work and decision-making beyond ERIGrid 2.0