Fraunhofer Center for Silicon Photovoltaics

Cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO) or life support (ECLS) circuits are built from polymers and might release polymeric micro- and nanoparticles (MNP) into the circulation. MNPs seem to provoke inflammation, oxidative stress, and apoptosis, which are also side effects of extracorporeal circulation. Thus, we investigated the MNP release from CPB and ECMO/ECLS circuits. A CPB and ECMO/ECLS circuit was filled with saline solution, and circulation was initiated for 5 h and 7 d, respectively. Samples were taken from both circuits and filtered through a silicon membrane. MNPs were detected and quantified using optical microscopy and micro Raman spectroscopy. During circulation, polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) were detected in the CPB perfusate. After 5 h of circulation, polyethylene terephthalate (PET) was detected. In the ECMO/ECLS circuit, time-dependent accumulation of polymeric fragments was detected. Finally, particles of polyethylene (PE), polystyrene (PS), PET, and PVC were identified. The particle-size distribution extended from initially <2 µm to finally >10 µm with increasing circulationtime. CPB and ECMO/ECLS circuits release MNPs. The number of MNPs increases over the period of use. A larger number of circuits and of health effects of identified MNPs, should be investigated.

• Performance of new dust mitigation strategy on PV Modules based on natural resuspension of dust. • Compares experimental results from the laboratory with outdoor tests. • Proof of the potential to reduce dust by 91%. • Describing dependencies on environmental conditions such as wind direction and wind speed. • Smart heating as a mitigation strategy leads to a negative energy balance of PV systems. Soiling impairs the energy yield of photovoltaic systems, particularly in arid and semi-arid regions. The primary scientific focus is therefore on the development of efficient cleaning technologies. Complementarily, this work considers a strategy for mitigating soiling through smart heating of photovoltaic modules. The findings suggest that the combination of heated photovoltaic modules with favorable wind conditions can lead to a reduction in dust accumulation. This reduction has the maximum potential to generate an estimated solar energy gain of up to 0.064 kWh/m 2 per day. However, a comprehensive evaluation of laboratory tests and outdoor experiments conducted in Morocco reveals an overall negative energy balance of −0.24 kWh/m 2 per day. The heating system consumed more energy than it mitigated soiling-losses. The study demonstrated that low wind speeds of less than 2.7 m/s and unfavorable north wind directions are unsuitable for generating significant resuspension effects despite heating. Consequently, the economic viability of this technology remains uncertain under real-world conditions. Furthermore, the study emphasizes the limitations of the proposed mitigation strategy and identifies the reasons for the overall negative energy yield.

A global challenge of our nowadays life is dealing with micro- and nano-plastic particles (MNPs), due to wide spreading all around us, persistence over the years, and toxic character, contributing to adverse effects on human health. As one of the biggest polluters worldwide, the textile industry including mechanical and chemical processes of fibers and garments generates various contaminants in the indoor air, including �white pollutants� with micro-nano plastic particles MNPs. This paper presents some methods for the collection of airborne plastic particles, which are generated near workplaces in the Romanian textile industry that mainly process polyester (PES) / polyethylene terephthalate (PET) yarns/fibers. A GilAirPlus � unplugged, device, equipped with QuadModeSM air sampling technology, up to 1 l/min constant airflow was used for the experiments, at 2 different working times (T1-T2) corresponding to the working shifts of the day. The selective airborne MNP sampling of 1 �m and 10 �m was done using a specially designed and developed holder system, on silica (Si) filters with a pore size of 0.8 �m and a diameter of 9 mm, according to the specific procedure (SOP) of collection. The analysis of the morphological structure of the MNPs was performed using scanning microscopy (SEM) and �-RAMAN spectroscopy methods, and it was evidenced that the particles have, in general, a spherical shape, with an average size close to 10 �m.

Defect engineering plays a critical role in two-dimensional (2D) semiconductor devices, especially for 2D transition-metal dichalcogenides (2D-TMDs) due to their extraordinary optoelectronic properties. However, directly comparing defect-related effects on various devices presents challenges, as it requires multiple growth processes and device fabrication procedures including stacking. Here, we have designed and produced one platform for 2D-TMD multijunction MoS2−MoS2/WS2−WS2/WS2−WS2 on a single flake via chemical vapor deposition (CVD) growth to investigate its photoexcited carrier dynamics. Ultrafast pump-probe transient transmittance measurements at four junctions reveal the defect-related effects on fast and slow relaxation processes and further uncover passivation occurring at the MoS2/WS2 junction, with a longer relaxation time of 25 ps. This work paves the way to establish a paradigm for examining charge-carrier dynamics in functionalized 2D van der Waals multijunctions via CVD growth and a unique microscopic method. Published by the American Physical Society 2025

This paper addresses the growing concern surrounding microplastic pollution, particularly within the textile industry, and the associated potential health risks linked to the inhalation and ingestion of microplastic particles. Microplastics, defined as plastic particles smaller than five millimeters, are increasingly found not only in aquatic environments, but also in soils, air, and food. Although research on the health impacts of microplastics is still emerging, early studies indicate that these particles could contribute to health issues, including oxidative stress, inflammation, and cardiovascular diseases. Notably, individuals with higher concentrations of plastics in arterial plaques are more susceptible to heart attacks and strokes. In the textile industry, synthetic fibers such as polyester, nylon, and acrylic release microplastics into the air during production. The paper discusses a study conducted in a textile company that processes polyester yarns, where airborne microplastic concentrations were measured at various locations throughout the day. Particle sizes ranging from 0.3 nm to 10 nm were analyzed, revealing the presence of polyester polymers in the particulate matter. These findings underscore the widespread nature of microplastic pollution, particularly in industrial settings, and raise concerns about the health risks associated with prolonged exposure to airborne microplastics. While further research is necessary to fully understand the extent of these health impacts, preliminary data suggest a troubling link between microplastic inhalation and cardiovascular conditions.

Next generation solar cells like tunnel oxide passivated contacts (TOPCon) or perovskite/TOPCon tandem solar cells require efficient interface passivation by ultrathin organic or inorganic layers to uncover their true efficiency potential. Especially the microstructure and the Si suboxide content of the tunnel oxide in poly-Si(Ox)/SiO2/c-Si TOPCon stacks have been shown to have a tremendous influence on macroscopic device properties. Similarly, perovskite/ITO interface modification by a self-assembled monolayer (SAM) molecule is necessary to achieve high power conversion efficiencies of the perovskite sub cell. However, the characterization of such thin film structures and the interfacial composition is challenging. In this contribution, we present characterization results of ultrathin passivation layers using angle-resolved X-ray photoelectron spectroscopy (XPS) and advanced data evaluation routines, including maximum entropy methods and analyses of inelastically-scattered electron background data. In particular, the interfaces in the stacks (1) partially oxidized a-Si/SiO2/c-Si and (2) 2PACz/ITO after different thermal treatment were investigated. It could be shown that already a ~5 nm thin SiNx layer prevents unwanted oxidation from ambient during cooldown of TOPCon-like stacks and that annealing above 100 °C can convert a 2PACz multilayer to a 2PACz monolayer on an ITO substrate.

Decarbonizing electricity generation is crucial for achieving sustainable development. In this context, photovoltaic (PV) technology plays a vital role because of its technological maturity and widespread adoption among stakeholders. Currently, the design of PV systems focuses on maximizing the energy conversion of PV modules. However, as the integration of PV systems increases, a paradox arises: while there is a need to inject more renewable energy into the grid, the mismatch between generation and demand creates challenges for grid integration.Reducing the cost of PV power generation could facilitate the integration of more electricity into the grid by allowing a compromise in production. This approach could enable more efficient use of generated energy and better grid integration. Therefore, this study presents an introductory sensitivity analysis through computational simulations exploring various orientations (azimuth and tilt angles) for bi-particle photovoltaic systems and their corresponding impact on grid integration. This exercise was conducted using the load demand profile for Costa Rica in 2023. Using this analysis, it was found the theoretical maximum PV capacity to be installed in Costa Rica is around 2GWp. Also it is found that the better utilization of the PV generation occurs for lower tilt angle with some not wide penetration for vertical bifacial systems.

In this work, two different anti-soiling coatings (ASC) and anti-reflection coatings (ARC) were developed and tested under real operating conditions in Doha, Qatar, and compared with uncoated glass (UNC) to identify the best coating properties for mitigating solar photovoltaic (PV) module soiling. Soiling was measured in terms of loss in light transmittance, measured by UV–Vis spectroscopy, and increase in surface coverage area, measured using optical microscopy. The results indicate a decrease in light transmittance and an increase in surface coverage area over time due to dust accumulation. ASC coupons show higher hydrophilicity and, therefore, less soiling. ASC/ARC leads to a higher loss in light transmittance, while UNC results in a higher surface coverage area compared to the other coupons. Over 25 weeks of outdoor exposure and 12 cleaning cycles, analysis of 13,320 light microscopy images revealed mean dust surface coverage areas for ASC, ASC/ARC, and UNC glass coupons of 14.6 %, 13.6 %, and 15.8 %, respectively. Unlike the ASC/ARC and UNC coupons, the ASC recovers to its initial condition immediately after cleaning. Therefore, ASC was found to maintain a cleaner glass surface compared to ASC/ARC and UNC. However, the differences in transmittance loss among the three coupons are not significant. The results were compared to findings from similar studies conducted in Saudi Arabia to evaluate regional differences in coatings performance. For the same coatings, a significant light transmittance loss was measured in Doha (Qatar) compared to Uyaynah (Saudi Arabia). The combination of high humidity and heavy dust in Qatar's extreme conditions reduces the effectiveness of both ASC/ARC and ASC coatings.

Photoferroelectric BiFeO3 (BFO) has attracted renewed interest to be integrated into thin film photovoltaic (PV) devices as a stable, lead-free, and versatile photoabsorber with simplified architecture. While significant efforts have been dedicated toward the exploration of strategies to tailor the properties of this photoabsorber to improve the device performance, efficiencies still remain low. The modification of the BFO interface by the incorporation of transport-selective layers can offer fresh opportunities to modify the properties of the device. Identifying an optical and electrically suitable selective layer while ensuring easy device processing and controlled film properties is challenging. In this work, we determine the influence of incorporating a ZnO layer on the ferroelectric and photoresponse behavior of an epitaxial BiFe0.9Co0.1O3 (BFCO)-based heterostructure. The device is completed with Sn-doped In2O3 (ITO) and La0.7Sr0.3MnO3 (LSMO) electrodes. This all-oxide system is stable under ambient conditions and displays robust ferroelectricity. The coupled ferroelectricity-photoresponse measurements demonstrate that the short circuit current can be modulated by ferroelectric polarization in up to 68% under blue monochromatic light. Also, the responsivity of the system with the ZnO-modified interface is larger than that of the system with no ZnO. Complementary band energy alignment studies reveal that the observed increase in the short circuit current density of the device with ZnO is attributed to lower Fermi level energy at the ZnO/BFCO interface compared to the ITO/BFCO interface, which reduces charge recombination. Therefore, this study provides useful insights into the role of the ZnO interface layer in stable BFO-based devices to further explore their viability for potential optoelectronic applications.