In order to surpass the Shockley-Queisser limit on power conversion efficiency, schemes to manipulate high- and low-energy photons must be developed. In this talk, I will describe our use of crystal engineering techniques to enhance the singlet fission process, where one high-energy singlet exciton is converted into two lower-energy triplet excitons. Structural modifications that enhance and accelerate this process will be described, along with approaches to harvest the 'dark' triplet states formed by the fission process. I will also describe our search for new chromophore systems that allow triplet-triplet annihilation, which is a process where very low energy triplet excitons, too low in energy to be harvested by Si-based photovoltaics, can be combined into a higher energy photon that is able to be absorbed.

Radiation therapy is an effective medical procedure for cancer treatment that relies on the fact that high-energy ionizing radiation can destroy cancer cells. Nevertheless, the risks of malignancies induced by peripheral radiation in healthy tissues surrounding the target volumes represents a serious concern for all patients and doctors alike. Positioning of the patient, inhomogeneities in the target (muscles/bones/adipose tissue), and even minor movements (e.g. breathing), can alter the received dose and targeted volume, and thus affect the outcome of the procedure. Therefore, being able to measure radiation doses with high accuracy and in real time is a critical aspect of diagnostics and treatment. In this presentation I will introduce a new type of radiation dosimeter, the RAD-OFET (RAdiation Detector based on Organic Field-Effect Transistor), which can validate in real time the dose being delivered and ensure that for nearby regions an acceptable level of low dose is being received. The RAD-OFETs exploit trap generation/annihilation in organic semiconductors, are sensitive to doses relevant to many radiation treatment procedures and are robust when incorporated into conformal large-area electronic applications. Placement of the sensor directly onto the human body, coupled with the similarity in the Z-number between the electronically active layer and the human tissue, allows for direct measurement of the radiation dose, eliminating the need for extensive data processing faced by current technologies. The direct consequence is a greater precision and lower complexity in the medical equipment: their adoption in clinical settings will facilitate the application of therapeutic radiation with high precision, a process that will increase the effectiveness on treating cancerous tissue and minimize the impact on the surrounding healthy cells. These results uncover new opportunities for organic circuits that will improve the quality of healthcare through better, lower cost in vivo dose monitoring during radiation therapy.

Emerging PV technologies cells have a continuous strong track record in performance during the last years. With these performance values, solution processed emerging photovoltaic technologies are reaching out to applications that are going beyond the typical niche markets. The first generation of commercially available printed PV modules showed a lifespan in the order of beyond 5 years and more under outdoor conditions (OPV) while long-time outdoor data for perovskite modules are still missing. Interestingly, several experiments are strongly suggesting that solution processed semiconductors like organics or perovskites can be stable under light and, to some extent, under oxygen as well. Despite these impressive numbers, one should not forget that these are “best you can do” lifetime values. On the other hand, the community did not progress significantly in overcoming the fundamental limitations of printed PV. This is more expressed for organics than for perovskites: The energy gap law for excitonic materials, the precise microstructure control of binary or ternary composites, the design principles for environmentally stable materials or the Kirchhoff law for multi-junction cells continue to be major barriers for this technology. We briefly introduce into these long-time challenges and then discuss concepts and strategies how to resolve them for excitonic absorbers. Among them, the development of a digital twin which has inverse predictive power is a most promising concept. “Solar FAU”, an alliance of research partners in the Erlangen-Nürnberg region that is headed by Friedrich Alexander University, is exploring the basic concepts and methodologies how to build a digital twin for emerging-PV technologies. The central and most desired element of the digital twin is the power of inverse design, e.g., inventing molecules, device architectures and processes with tailored properties. Insight from first pieces (agents) of the digital twin strongly supports the assumption that inverse design capability is possible, even in the case of considerable experimental uncertainty. Coupling the digital twin to Material Acceleration Platforms (MAP) reduces experimental uncertainty and allows to learn predictions which otherwise would be impossible. We have recently demonstrated the power of such coupled systems and demonstrated correlations which were previously unthinkable, like the prediction of performance and lifetime of OPV cells from simple absorption data or the identification of he best process for perovskites under environmental conditions merely at the hand of photoluminescence data.

According to a United Nations report, chemicals production and consumption are to be doubled in the next 10 years to fulfil our essential needs. It’s simply not going to happen unless we adopt a circular economy approach. The UKRI Interdisciplinary Centre for Circular Chemical Economy was established in January 2021 to kick start the timely transition of the UK’s £32bn chemical industry into a circular system. In this talk, I will outline the vision and remit of the Centre, and discuss why we need a whole system approach and an interdisciplinary team to address the challenge. I will then give some examples of the on-going research in our lab to tackle the challenges in the development of the circular chemical economy. I will show how we combine classic electrochemical engineering with cutting-edge enabling tools such as deep learning and digital twin technologies to deliver novel sustainable chemicals and materials and recover chemical feedstocks from end-of-life materials and captured CO2 emissions.

Under the increasingly severe climate and regulative pressures to achieve carbon neutrality, current electrochemical energy storage systems are in need of a radical upgrade to meet various demands from end users. Aqueous zinc ion batteries (AZIBs) provide sustainable routes to grid-scale energy storage because of their cost and safety advantages, using mild aqueous electrolytes and abundant metallic zinc anodes. Besides, owing to the distinctive merits such as relatively high ionic conductivity, environmental benignity, low risks of flammability and considerable energy density of AZIBs compared with conventional Li-ion batteries, AZIBs are intensively investigated to unleash the potential for practical applications. However, the development of rechargeable AZIBs is plagued by poor reversibility due to a series of intrinsic issues, such as hydrogen evolution and Zn dendrite formation. Significantly, the advances in materials discovery and innovation in device configuration have improved the performance of AZIBs in all aspects, including durability, operating voltage range, energy/power density, and economic availability. Different electrolyte components are investigated intensively to suppress the side reaction on the Zn anodes. However, further improvements are needed, especially for realizing the requirement for high energy density and high stability scenarios. The recent progress of AZIBs technology, such as facile electrolyte components and additives for aqueous AZIBs will be discussed in this talk.

Because of long lifetime objectives and cost control, encapsulation is a critical point for the commercialization of perovskite PV technologies. Indeed, degradation mechanisms related to atmosphere ingress requires the use of high gas barrier materials which prevent the diffusion of gases for decades and the development of encapsulation methods which wont damage the devices. In this talk, after introducing the topic, we will highlight some methods we developed in CEA in order to assess encapsulating materials and how it could help to establish efficient encapsulation strategies with a controlled cost.

Location: Plaza in front of the Building 18.

Location: Lobby area of the seaside of Level 2, Building 5.

To devise a sustainable energy portfolio under the planetary and practicality constraints, we must consider a hybrid model of renewable-energy-powered low-carbon fossil fuel production as a transitional energy technology. Such untethered demand would also provide the natural growth and gradual implementation flexibility that the green hydrogen industry needs to build to scale. At the heart of a potential transitional energy technology platform is synthesis gas (syngas), a mixture of gaseous carbon monoxide and hydrogen. Syngas is currently the primary source of hydrogen for fuel cell vehicles and has been the core building block in the chemicals industry for liquids, particularly alcohols, olefins, and low molecular weight fuels. We have recently developed a Ni-Mo-MgO nanocatalyst that facilitates syngas production from the dry reforming of methane without coking or sintering, even after 35 days of continuous operation. Since it is known that switching syngas production from steam reforming to dry reforming could provide gigatons of CO2 avoidance without significantly altering our lifestyle, this emissions relief could provide the necessary time for a successful implementation of future energy technologies. In such a syngas economy, chemicals and transition fuels would be made using syngas from dry reforming of hydrocarbons and green hydrogen water electrolysis. An estimated 15-50% reduction in carbon emissions is possible without any change to the infrastructure. Further reductions would be introduced if syngas was produced from a range of sources, such as biomass, waste, plastics, or paper, and the direct conversion of syngas to more chemicals was feasible.

There is increasing interest in harnessing sunlight to drive the synthesis of molecular fuels and chemicals, including in particular water photolysis to yield molecular oxygen and hydrogen. This can be achieved either through the coupling of photovoltaic cells and electrolysis, or through direct sunlight conversion by photoelectrodes or photocatalysts, the latter being the focus of this talk. In solar conversion, there is often a critical kinetic mismatch between the lifetimes of initially generated photoexcited states and the timescales of charge extraction / catalysis. I will start my talk by introducing solar driven fuel synthesis, and the charge carrier lifetime challenge in photoelectrochemical and photocatalytic systems. I will contrast this with the smaller lifetime challenges in organic and perovskite solar cells. I will then go on to discuss some of our recent studies employing transient optical spectroscopies measuring charge carrier dynamics in photoelectrodes and photocatalysts and how these impact upon the efficiency of solar driven water splitting, covering a range of metal oxide and polymer materials. I will consider the importance of d-orbital occupancy in metal oxide photocatalysts in determining charge carrier lifetimes. I will then go on to discuss carbon nitride and organic polymer photocatalysts, and the impact of charge trapping and heterojunctions in extending the lifetime of charge carriers. I will conclude by contrast charge carrier dynamics on organic bulkheterojunction solar cells and photocatalysts nanoparticle suspensions, and in particular the ability of aqueous environments to supress charge carrier recombination.

Reduction of carbon dioxide has as main objective the production of useful organic compounds and fuels - renewable fuels - in which solar energy would be stored. Molecular catalysts can be employed to reach this goal, either in photochemical or electrochemical (or combined) contexts. They may in particular provide excellent selectivity thanks to easy tuning of the electronic properties at the metal and of the ligand second and third coordination sphere. Recently it has been shown that such molecular catalysts may also be tuned for generating highly reduced products such as formaldehyde, methanol and methane, leading to new exciting advancements. Likewise, hybridization of these catalysts with conductive or semi-conductive materials may lead to enhance stability and new catalytic properties, as well as the development of devices for applications.This strategy bridges between homogeneous and heterogeneous catalysis, and it raises fundamental questions that may further lead to breakthrough in CO2 reduction chemistry. Our recent results in these various areas will be discussed, using earth abundant metal (Fe, Co) porphyrins and phthalocyanines as well as related polypyridine based catalysts.

The OPV technology is in constant development and in early market adopters’ installations. Throughout the last seven years, Sunew is strongly leading the market expansion and the OPV volume production with more than 18.000m² of OPV produced. To achieve these marks, Sunew focused on developing robust process procedures, rigorous quality control methods and validated testing protocols to guarantee uniformity from batch to batch, independent of external factors. A presentation and discussion of the production process evolution throughout the years, how to keep up with the technology's constant innovation, the challenges from simple scaling up of ink preparation to complex understanding of the effect of high voltage and current on the organic panel durability.

Ever since the demonstration of the first organic photovoltaic (OPV) cell in the late 1980s, there has been the vision of low-cost solar electricity generation from thin, lightweight, flexible and sustainable devices. Global megatrends demand such products as they provide aesthetic value to objects, structures and buildings besides pure energy harvesting. Nowadays, customized OPV has become a unique solution besides other well-known photovoltaic technologies. The ability to translate thin photoactive films into any shape and their integration into any kind of surface is a game changer and creates a paradigm shift in the energy sector as energy can now be generated and consumed directly at the point of use. The talk will focus on ASCA’s pioneering work in the commercialization of OPV and the numerous projects realized within the latest years that showcase the market readiness of the technology. In addition, technological and manufacturing process related innovations and trends will be discussed.

It will be demonstrated the development of a series of conjugated polymers based on the donor-acceptor (D-A) approach consisting of benzodithiophene and quinoxaline derivatives as the electron rich and deficient building block that when employed as electron donor components at organic solar cells exhibit high performance and stability, simultaneously. Moreover, it will be shown how the highest occupied molecular orbital (HOMO) can be precisely control by only an atom change at the side substituents. This allowed for a detailed analysis when matching the energy levels of polymer donors and small molecule acceptors. Therefore, we were able to investigate organic solar cells with highest occupied molecular orbital energy level offsets (ΔEHOMO) between 0 - 300 meV. It will be shown that exciton quenching at negligible ΔEHOMO takes place on timescales approaching the intrinsic exciton lifetimes, drastically limiting external quantum efficiency. This finding it is quantitatively described via the Boltzmann steady-state equilibrium between charge transfer states and excitons and further reveal a long exciton lifetime as a decisive design criterion for maintaining efficient charge generation at negligible ΔEHOMO. Moreover, the Boltzmann equilibrium quantitatively describes the major reduction in non-radiative voltage losses at very small ΔEHOMO.

Currently global government and private industrial investments in renewable energy are ramping up due to rising climate concerns and Net-Zero commitment. Solar PV technologies are low-carbon solutions, yet the carbon footprint of conventional solar panels can be quite significant due to toxic materials and their manufacturing process. In this presentation, we’ll compare how CO2 is saved with alternative solar energy with solar panel carbon footprints. Recently, top manufacturers are trending towards a low cost, light weight, and shape transformable integrated solution. Therefore, a thin flexible printable photovoltaic cell has great potential to be the top choice for the future generation solar cell market leaders. The local R&D initiatives in OPV technology are aligned with Saudi Aramco future focus on Non-metallic materials use of its oil resources. Most of the mass of OPV type solar cell is consisted of petrochemical-based organic materials in the recent configuration. Mega Construction projects and smart city trends in GCC, will increase demands for Solar energy, which offers high potential in values chain processes, localization output, market transformation and sustained growth. it was estimated that Billions of Square meters of unused building surfaces are available for OPV type module application, most of which is not suitable for conventional Solar Panels. A business case was estimated for OPV solar module and investment opportunities were explained. We’ll discuss solar emissions impacts and discuss some local market trends on sustainable technologies in relation with localization prospects.

Seaside atrium of University Library