Carlo Spampinato

Semitransparency is essential for applications in agrivoltaics and building-integrated photovoltaics. Here, semitransparent perovskite solar cells (PSC) are developed using high-vacuum sputtering deposition of advanced oxide layers. The bottom electrode is a Gig-Lox TiO2 multibranched sponge deposited on commercial c-TiO2/FTO by reactive sputtering. This sponge is then infiltrated with δ-CsPbI3, which remains mostly embedded into the TiO2 scaffold during the subsequent deposition steps. On top of this stack, a transparent 7 nm MoOx buffer layer is deposited at low power density in pure Ar from a MoO3 target, followed by the deposition of a 90 nm-thick ITO layer by reactive sputtering in Ar–O2. The resulting device can be described as an HTL-free-like architecture, where the ultrathin MoOx layer enables hole transfer into ITO via defect-assisted tunneling. The perovskite, initially in the nonphotoactive δ-phase, is converted into the photoactive γ-phase upon annealing the full FTO/c-TiO2/Gig-Lox TiO2/CsPbI3/MoOx/ITO stack at 350 °C. Full device annealing is enabled by the inorganic nature of the entire stack, and reannealing is also feasible at the same temperature for reuse. Simulations and experiments suggest that an interplay between the Gig-Lox TiO2 thickness and the MoOx interlayer modulates both transmittance and PSC efficiency by tuning the CsPbI3 Fermi level and the CsPbI3/MoOx interface dipole. The proposed reusable, fully sputtered semitransparent PSC architecture integrating CsPbI3 opens applicative perspectives in building-integrated photovoltaics and agrivoltaics.

Semi-transparent electrodes are a key enabling component for optoelectronic and photovoltaic architectures requiring light coupling through the top contact. Here, copper ultrathin films were deposited by thermal evaporation on glass substrates, systematically varying the thickness (40, 100 and 250 nm), and assessed through a combined structural, morphological, chemical and optoelectronic characterization. X-ray diffraction shows the formation of polycrystalline fcc Cu with the expected (111), (200), and (220) peaks, while scanning electron microscopy reveals compact, nanogranular morphologies whose continuity increases with homogeneity. X-ray photoelectron spectroscopy indicates the presence of surface oxidation/adsorbates in air-exposed films, highlighting the relevance of surface chemistry for contact engineering. Electrical measurements show a strong reduction of sheet resistance with thickness (from ∼30 Ω/□ at 40 nm to ∼0.5 Ω/□ at 250 nm), while optical transmittance in the visible decreases accordingly, making the thinnest film the most suitable compromise for semi-transparent operation. These results provide practical design guidelines and quantitative benchmarks for implementing evaporated copper as a cost-effective semi-transparent electrode in PV-related and general optoelectronic devices.

All-inorganic cesium lead iodide (CsPbI₃) has been investigated for more than a decade as an absorber for perovskite photovoltaics thanks to its attractive bandgap, thermal robustness compared with hybrid perovskites, and compatibility with tandem concepts. Yet, despite remarkable efficiency progress, CsPbI₃ remains far from widespread commercialization. The core roadblock is the metastability of the photoactive black perovskite phases (α/γ/β) against transformation to the photoinactive yellow δ-phase under realistic conditions, amplified by defect chemistry, ion migration, and interfacial reactions. Additional barriers arise from scale-up constraints (film uniformity, throughput, solvent management), long-term operational stability (humidity, heat, UV, bias), and environmental/safety requirements, especially lead containment, sequestration, and end-of-life strategies. This review critically analyzes the intertwined physical, chemical, and engineering factors that still limit CsPbI₃ deployment, with emphasis on how solutions in one domain can fail without co-design in others. This review summarizes state-of-the-art stabilization strategies (size/strain engineering, additive/doping routes, surface/interface passivation, and encapsulation), highlight scalable manufacturing pathways including solvent-minimized and vacuum-assisted approaches, and discuss lead-mitigation technologies such as Pb-adsorbing functional layers. Finally, I argue that artificial intelligence (AI)—from machine-learning stability models to process monitoring, robotic optimization, and digital twins—has become essential to navigate the enormous parameter space of CsPbI₃ materials and manufacturing. It concludes with actionable recommendations and future directions toward bankable, scalable, and sustainable CsPbI₃ photovoltaics.

Societal Impact Statement: The increasing demand for sustainable food production requires innovative solutions that balance productivity, resource efficiency, and environmental impact. Vertical farming systems (VFSs) offer a promising approach; however, their high energy consumption remains challenging. Here, we explore the potential of integrating advanced photovoltaic technologies such as dye‐sensitized and perovskite solar cells to power energy‐efficient LED illumination systems in agrivoltaics. The optimization of LED spectral “recipes” to enhance plant growth and nutritional quality is introduced. Coordinated research bridging materials science, photobiology, and photophysics, along with targeted urban planning and policy support, can enable VFSs and agrivoltaics to enhance resilience in high‐density urban areas. Summary: Climate change, urbanization, and population growth urgently require the development of innovative agricultural solutions to ensure sustainable food production. Vertical farming systems (VFSs) represent a promising solution to enhance crop productivity irrespective of seasonal variations, weather conditions, or geographical constraints, while simultaneously conserving water and minimizing the use of chemical inputs. By enabling precise control over environmental factors such as radiation spectra, temperature, and CO₂ concentrations, VFS can increase crop yields through local production and improve nutritional quality by enhancing the synthesis of secondary metabolites in plants. One of the primary challenges associated with VFS is the high energy demand required for plant lighting and temperature regulation. Light‐emitting diodes (LEDs) play a pivotal role in addressing this issue due to their energy efficiency and the ability to manipulate radiation spectra. The spectral quality of LED radiation can modulate distinct biological responses in plants, which may, in turn, lead to increased biomass production and enhanced biosynthesis of bioactive compounds with nutraceutical value. However, achieving energy sustainability in VFSs requires the integration of advanced photon‐to‐electron conversion technologies. Hybrid perovskite solar cells (PSCs) and dye‐sensitized solar cells (DSSCs) are among the most promising technologies for addressing the energy demands of VFS. These advanced solar cells efficiently harvest sunlight to power LEDs, thereby optimizing radiation quality for plant growth while reducing dependence on external energy sources. By coupling these renewable energy technologies with VFS, the overall sustainability and efficiency of food production systems can be significantly improved, contributing to the development of resilient agricultural practices in response to global challenges.

In this study, we propose a novel approach where in an innovative porous grazing incidence atomic flux coupled with local oxidation (gig-lox) TiO₂ electron transport layer (ETL), deposited by sputtering, is integrated with a fully inorganic CsPbI₃:EuI₂ perovskite. This combination is used as a photoactive layer in semitransparent perovskite solar cells (ST-PSC). The solvent-free, scalable porous oxide sponge-like in structure, is produced via a grazing-incidence Ti flux that undergoes localized progressive oxidation. The sponge offers ≈50% volume porosity that is available for perovskite infiltration. The result of the oxide-perovskite integration is a double-layer struc made of a perovskite-filled sponge covered by a cap of pure perovskite. The material has unique optical properties and structure as attested by spectroscopic ellipsometry and X-ray diffraction analyses. The double-layer structure exhibits semitransparency, and its reduced photoluminescence (PL) intensity relative to that of a single perovskite layer indicates efficient charge carrier injection into the porous TiO₂. In perspective, the layer can be used in PSC as demonstrated by simulations.

Agrivoltaics, integrating photovoltaic systems with crop cultivation, demands semitransparent solar modules to mitigate soil shadowing. Perovskite Solar Cells (PSC) offer competitive efficiency, low fabrication costs, and high solar transmittance, making them suitable for agrivoltaic applications. However, the impact of PSC light filtering on plant growth and transcriptomics remains underexplored. This study investigates the viability and agronomic implications of the growth of radicchio seedlings (Cichorium intybus var. latifolium) in laboratory-scale greenhouses integrating Perovskites-coated rooftops. Eu-enriched CsPbI₃ layers are chosen to provide semi-transparency and phase stability while radicchio has limited size and grows in pots. Despite the reduced light exposure, radicchio seedlings exhibit faster growth and larger leaves than in the reference, benefiting from specific spectral filtering. RNA-sequencing reveals differential gene expression patterns reflecting adaptive responses to environmental changes. Simulations of full PSC integration demonstrate a positive energy balance in greenhouses to cover annual energy needs for lighting, irrigation, and air conditioning.