452 research outputs found
Graphene-Based Interconnects for Stable Dye-Sensitized Solar Modules
We present Z-Type Dye Sensitized Solar Modules (DSSMs) with screen printed graphene-based vertical interconnects. This prevents corrosion of interconnects in contact with electrolytic species, unlike conventional Ag interconnects. By enlarging the width of single cells, or by increasing the number of cells, we get an enhancement of the aperture power conversion efficiency similar to+12% with respect to Ag-based modules, with 1000 h stability under 85 degrees C stress test. This paves the way to original design layouts with decreased dead area and increased generated power per aperture area
Emerging Thin Film Solar Panels
Utilizing of photovoltaics (PVs) has been rapidly developing over the past two decades due to its potential for transition from fossil fuels to renewable energy based economies. However, PVs as fuel less energy sources will be sustainable if some issues such as raw materials abundance, production cost, and environmental impacts carefully addressed in their value chains. Among PV technologies, thin film solar panels have been illustrated the potential to reach the sustainability. In this chapter we review some studies about environmental impacts of thin film PVs through life cycle assessment (LCA) and some environmental fate modeling. For the PV technologies, LCA studies need to be conducted to address environmental and energy impacts and encourage the development of PV technologies in a better sustainable way. Three methods of impact assessment in LCA are reviewed and compared, namely, Energy Payback Time (EPBT), Cumulative Energy Demand (CED), and Greenhouse Gases (GHG) emission rate, owing to data and information published in the literature. Generally, most results show promising potential of emerging thin film PVs, especially perovskite solar cells, to reach the best sustainable solution among PV technologies in near future
Stability of dye-sensitized solar cells under extended thermal stress
In the last few decades, dye-sensitized solar cell (DSC) technology has been demonstrated to be a promising
candidate for low cost energy production due to cost-effective materials and fabrication processes. Arguably,
DSC stability is the biggest challenge for making this technology appealing for industrial exploitation.
This work provides further insight into the stability of DSCs by considering specific dye–electrolyte
systems characterized by Raman and impedance spectroscopy analysis. In particular, two rutheniumbased
dyes, Z907 and Ru505, and two commercially available electrolytes, namely, the high stability
electrolyte (HSE) and solvent-free Livion 12 (L-12), were tested. After 4700 h of thermal stress at 85 1C, the
least stable device composed of Z907/HSE showed an efficiency degradation rate of B14%/1000 h, while
the Ru505/L-12 system retained 96% of its initial efficiency by losing B1% each 1000 h. The present
results show a viable route to stabilize the DSC technology under prolonged annealing conditions
complying with the IEC standard requirements
Graphene-Based Interconnects for Stable Dye-Sensitized Solar Modules
We present Z-Type Dye Sensitized Solar Modules (DSSMs) with screen printed graphene-based vertical interconnects. This prevents corrosion of interconnects in contact with electrolytic species, unlike conventional Ag interconnects. By enlarging the width of single cells, or by increasing the number of cells, we get an enhancement of the aperture power conversion efficiency ∼+12% with respect to Ag-based modules, with 1000 h stability under 85 °C stress test. This paves the way to original design layouts with decreased dead area and increased generated power per aperture area
New devices for energy harvesting and storage: integrated third generation photovoltaic solar cells and electrochemical double layer capacitors
A worldwide conversion towards renewable energy sources has to be implemented in order to hopefully avoid the irreversible consequences of the global temperature increment caused by the greenhouse gases production.
In addition, the current need to benefit from electricity in every moment of daily life, mainly in case of limited access to the electric grid, is forcing the scientific community to an intensive effort towards the production of integrated energy harvesting and storage devices.
The topic of this PhD thesis is to investigate and propose innovative solutions for the integration of third generation photovoltaic (PV) cells and electrochemical double layer capacitors (EDLCs), the so-called photo-capacitors.
Different photo-capacitor structures have been studied and experimentally fabricated. At first, flexibility was explored, as it is a mandatory requirement to cover non-planar or bendable surfaces, which are more and more common in nowadays portable electronics. Easily scalable fabrication processes have been used for both the harvester and the storage units, employing photopolymer membranes as electrolytes and metallic grids as current collectors and electrodes substrates. For this configuration, the best overall conversion and storage efficiency ever reported for a flexible Dye sensitized solar cell (DSSC)-based photo-capacitor was demonstrated.
Subsequently, observing in the literature an evident lack in the exploitation of high voltage photo-capacitors, EDLC electrolytes with broad voltage windows have been examined. These electrolytes allowed to fabricate stable and reliable devices integrating the EDLC with a PV module and not only with a single solar cell, as normally is done. High voltage values, up to 2.5 V, have been obtained employing an ionic liquid electrolyte (Pyr14TFSI) or –alternatively- a solid state electrolyte (PEO-Pyr14TFSI) for storage section fabrication.
Moreover, novel electrolyte mixtures of organic solvents and ionic liquids with good physical and electrochemical properties have been employed with the aim to increase energy density and voltage with respect to commercial EDLCs.
Finally, a novel polymer-based platform has been suggested for the fabrication of an innovative “two-electrodes” self-powered device. The multifunctional polymeric layer, made of two poly(ethylene glycol)-based sections separated by a perfluorinated barrier, was obtained by oxygen-inhibited UV-light crosslinking procedure. For the energy harvesting section, one side of the polymeric layer was adapted to enable iodide/triiodide diffusion in a DSSC, while the other side empowered sodium/chloride ions diffusion and was used for on-board charge storage. The resulting photo-capacitor results in a planar architecture appreciably simplified with respect to other recently proposed solutions and is definitely more easily exploitable in low power electronics
Fabrication and Optimization of Flexible Dye Sensitized Solar Cells
Ph.DDOCTOR OF PHILOSOPH
Roadmap on Photovoltaic Absorber Materials for Sustainable Energy Conversion
Photovoltaics (PVs) are a critical technology for curbing growing levels of
anthropogenic greenhouse gas emissions, and meeting increases in future demand
for low-carbon electricity. In order to fulfil ambitions for net-zero carbon
dioxide equivalent (CO2eq) emissions worldwide, the global
cumulative capacity of solar PVs must increase by an order of magnitude from
0.9 TWp in 2021 to 8.5 TWp by 2050 according to the International Renewable
Energy Agency, which is considered to be a highly conservative estimate. In
2020, the Henry Royce Institute brought together the UK PV community to discuss
the critical technological and infrastructure challenges that need to be
overcome to address the vast challenges in accelerating PV deployment. Herein,
we examine the key developments in the global community, especially the
progress made in the field since this earlier roadmap, bringing together
experts primarily from the UK across the breadth of the photovoltaics
community. The focus is both on the challenges in improving the efficiency,
stability and levelized cost of electricity of current technologies for
utility-scale PVs, as well as the fundamental questions in novel technologies
that can have a significant impact on emerging markets, such as indoor PVs,
space PVs, and agrivoltaics. We discuss challenges in advanced metrology and
computational tools, as well as the growing synergies between PVs and solar
fuels, and offer a perspective on the environmental sustainability of the PV
industry. Through this roadmap, we emphasize promising pathways forward in both
the short- and long-term, and for communities working on technologies across a
range of maturity levels to learn from each other.Comment: 160 pages, 21 figure
Solar Cells
The second book of the four-volume edition of "Solar cells" is devoted to dye-sensitized solar cells (DSSCs), which are considered to be extremely promising because they are made of low-cost materials with simple inexpensive manufacturing procedures and can be engineered into flexible sheets. DSSCs are emerged as a truly new class of energy conversion devices, which are representatives of the third generation solar technology. Mechanism of conversion of solar energy into electricity in these devices is quite peculiar. The achieved energy conversion efficiency in DSSCs is low, however, it has improved quickly in the last years. It is believed that DSSCs are still at the start of their development stage and will take a worthy place in the large-scale production for the future
Reliability and Ecological Aspects of Photovoltaic Modules
Photovoltaic (PV) solar energy is expected to be the world's largest source of electricity in the future. To enhance the long-term reliability of PV modules, a thorough understanding of failure mechanisms is of vital importance. In addition, it is important to address the potential downsides to this technology. These include the hazardous chemicals needed for manufacturing solar cells, especially for thin-film technologies, and the large number of PV modules disposed of at the end of their lifecycles. This book discusses the reliability and environmental aspects of PV modules
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