Organometal halide perovskite solar cells (PSCs) have emerged as promising candidates for next-generation thin-film solar cells. Over the past ten years, the efficiency of PSCs has increased from 3.8% to over 25% through the optimization of the perovskite film formulation and the engineering of suitable fabrication strategies and device architectures. However, the relatively poor long-term device stability, which has not been able to exceed some hundreds of hours until now, represents one of the key aspects still hampering their widespread diffusion to commercial contexts. After briefly introducing the origin and basic mechanisms behind PSC degradation and performance decline, a systematic outline and classification of the available strategies to improve the long-term stability of this class of photovoltaic devices will be presented, mainly focusing on encapsulation procedures. Indeed, the aim of this review is to offer an in-depth and updated account of the existing encapsulation methods for PSCs according to the present understanding of reliability issues. More specifically, an analysis of currently available encapsulation materials and on their role in limiting the penetration of UV light and external agents, such as water vapour and oxygen, will be proposed. In addition, a thorough discussion on various encapsulation techniques and configurations will be presented, highlighting specific strengths and limitations of the different approaches. Finally, possible routes for future research to enhance the effectiveness of the most performing encapsulation procedures will be suggested and new paths to be explored for further improvements in the field will be proposed.

Prolonged durability in outdoor environment and ease of application are highly required features for self-healing coatings. To this end, a novel transparent and self-healing nanocomposite for optical applications, based on Diels-Alder (DA) chemistry is developed in this work. First, a novel, highly soluble, bismaleimide enabled a simple coating fabrication by coupling with furan-functionalized polyacrylates in industrially relevant solvents. The resulting crosslinked coatings exhibited high transparency and complete absence of color, as assessed by UV-vis spectroscopy. Their thermal behavior and the conditions required by the healing process were significantly affected by the degree of furan/maleimide functionality of the system. Secondly, the addition of a small amount of a commercial antioxidant stabilized the optical properties against photo-oxidative weathering, both on clear and titania-pigmented coatings, as determined by colorimetric analysis. Finally, dispersion of silica nanoparticles in the DA-based matrix allowed to enhance the surface hardness of the coatings, while retaining the self-healing ability.

Potassium batteries show interesting peculiarities as large-scale energy storage systems and, in this scenario, the formulation of polymer electrolytes obtained from sustainable resources or waste-derived products represents a milestone activity. In this study, a lignin-based membrane is designed by crosslinking a pre-oxidized Kraft lignin matrix with an ethoxylated difunctional oligomer, leading to self-standing membranes that are able to incorporate solvated potassium salts. The in-depth electro-chemical characterization highlights a wide stability window (up to 4 V) and an ionic conductivity exceeding 10 À 3 S cm À 1 at ambient temperature. When potassium metal cell prototypes are assembled, the lignin-based electrolyte attains significant electrochemical performances, with an initial specific capacity of 168 mAh g À 1 at 0.05 A g À 1 and an excellent operation for more than 200 cycles, which is an unprecedented outcome for biosourced systems in potassium batteries.

Conjugated semiconducting polymers are key materials enabling plastic (opto)electronic devices. Research in the field has a generally strong focus on the constant improvement of backbone structure and the resulting properties. Comparatively fewer studies are devoted to improving the sustainability of the synthetic route that leads to a material under scrutiny. Exemplified by the two established and commercially available luminescent polymers poly(9,9-dioctylfluorene-alt-bithiophene) (PF8T2) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (PF8BT), this work describes the first examples of efficient Suzuki-Miyaura polycondensations in water, under ambient environment, with minimal amount of organic solvent and with moderate heating. The synthetic approach enables a reduction of the E-factor (mass of organic waste/mass of product) by 1 order of magnitude, without negatively affecting molecular weight, dispersity, chemical structure, or photochemical stability of PF8T2 or PF8BT.

framework, luminescent solar concentrators (LSCs) are a practical and versatile solution for the realization of buildingintegrated photovoltaics (BIPVs). [2] The idea behind the LSC concept is the replacement of large area PV modules with small solar cells positioned at the edge of a planar monolithic waveguide (e.g., a polymer-based thin-film deposited onto a glass substrate or a bulk plate) containing luminophore species. The luminophores absorb incident sunlight and emit photons which are redirected by total internal reflection toward the thin edges of the waveguide, where the PV elements convert the luminescent light into electricity. [3] Many different types of luminescent species (e.g., organic fluorophores, [4] perovskite nanocrystals, [5] carbon-dots, [6] and semiconductor quantum dots [7] ) have been extensively explored over the past decades in the attempt to achieve a combination of a broad absorption spectrum, a high light-harvesting efficiency, a high solid-state photoluminescence quantum yield (PLQY), and excellent photostability. [8] Nevertheless, the different luminophore-and waveguide-related loss pathways taking place in the LSC [8a,b,9a] still affect the optical performance of current systems and represent important obstacles to the sustainable commercialization of this technology.In this study, the design, fabrication, and characterization of semi-transparent large-area luminescent solar concentrators (LSCs) in thin-film configuration is reported, incorporating a novel organic luminophore (PFPBNT) emitter based on a π-conjugated core flanked by two naphthothiophene units obtained through a chemically sustainable synthetic approach. As found experimentally and validated through computational modeling, PFPBNT exhibits aggregation-induced emission (AIE) behavior, broad absorption in the UV-vis spectrum and significant Stokes shift (≈4632 cm -1 ), thereby making it an excellent candidate as luminophore in thin-film LSCs based on a poly(methyl methacrylate) (PMMA) matrix, where it is found to show good compatibility, homogeneous distribution, and excellent photostability. After extensive device optimization, PFPBNT/PMMA LSCs with suitable luminophore concentration (12.5 wt%) showed an internal photon efficiency of 17.3% at a geometrical gain of 6.25 under solar-simulated illumination. The size scalability of these systems was also evaluated by means of ray-tracing simulations on devices of up to 1 m 2 surface area. This work demonstrates semi-transparent large-area thin-film LSCs incorporating chemically sustainable AIEgen luminophores, thus opening the way to the development of synthetically affordable, efficient, and stable emitters for the photovoltaic field.