Periodic Reporting for period 1 - HEPAFLEX (High-Efficiency Perovskites on Flexible Substrates for Sustainable Applications)
Reporting period: 2023-11-01 to 2025-02-28
HEPAFLEX addresses the challenge of developing next-generation photovoltaic (PV) technologies that are efficient, sustainable, and scalable. Perovskite solar cells (PSCs) have shown high laboratory efficiencies, but commercial adoption is limited by scalability, stability, and environmental concerns. HEPAFLEX aims to overcome these barriers by developing flexible PSCs with ≥25% efficiency for small-area and ≥23% for large-area devices, long-term durability, and low environmental impact.
The project integrates materials science, green chemistry, device engineering, and recycling. Innovations include photonic annealing, green precursor synthesis, self-assembled monolayer (SAM) transport layers, and advanced encapsulation. These are complemented by life cycle and cost assessments. A multi-actor consortium ensures cross-sector impact, supporting EU Green Deal and strategic autonomy goals.
Key objectives include delivering high-efficiency flexible modules using non-toxic methods, improving operational stability, enabling closed-loop recycling, reducing toxic inputs, and benchmarking sustainability and cost versus current PV technologies.
The project integrates materials science, green chemistry, device engineering, and recycling. Innovations include photonic annealing, green precursor synthesis, self-assembled monolayer (SAM) transport layers, and advanced encapsulation. These are complemented by life cycle and cost assessments. A multi-actor consortium ensures cross-sector impact, supporting EU Green Deal and strategic autonomy goals.
Key objectives include delivering high-efficiency flexible modules using non-toxic methods, improving operational stability, enabling closed-loop recycling, reducing toxic inputs, and benchmarking sustainability and cost versus current PV technologies.
In the first reporting period (01/11/2023 – 08/02/2025), HEPAFLEX achieved progress across materials development, device engineering, and environmental safety.
In WP1, photonic annealing (FIRA) was optimized for perovskite films with uniform grains and reduced defects. Flexible substrates (PET, PEN, polyimide) and FA/Cs-based compositions were validated. Ferrocene-based SAMs with different anchoring groups were developed as hole transport layers; PDI-based materials were tested as low-temperature, water-processable ETL alternatives. Green synthesis of MAI, FAI, PbI2, and PbBr2 was scaled and characterized; 15 PILs were created for ink formulation. Large-area coatings (blade, slot-die, inkjet) under ambient conditions enabled fast perovskite crystallization (<1 min) on PET. Full stacks with PEDOT and screen-printed carbon reached >10% efficiency in small areas, with minimal loss in 5 cm² modules.
In WP2, early stability testing showed improved results with refined encapsulation. Devices stored in nitrogen retained 60% of initial PCE after 1000 hours; minimodules kept 80% outdoors after 10 days. Impedance spectroscopy, PLQY, and ideality factor analysis were implemented to monitor degradation. Guanidinium and acetamidinium doping enhanced photoluminescence recovery under damage. Encapsulation using parylene and dual-layer acrylate/PDMS demonstrated good Pb containment.
In WP3, PILs and green solvents enabled removal of perovskite and carbon layers. PbI2, Cs⁺, FA⁺, and Au were recovered; gold purification is being refined. Cation exchange resins showed success in capturing Pb. Toxicity monitoring was initiated, and SSbD templates shared. Inventories for LCA, LCC, and SLCA were compiled.
In WP1, photonic annealing (FIRA) was optimized for perovskite films with uniform grains and reduced defects. Flexible substrates (PET, PEN, polyimide) and FA/Cs-based compositions were validated. Ferrocene-based SAMs with different anchoring groups were developed as hole transport layers; PDI-based materials were tested as low-temperature, water-processable ETL alternatives. Green synthesis of MAI, FAI, PbI2, and PbBr2 was scaled and characterized; 15 PILs were created for ink formulation. Large-area coatings (blade, slot-die, inkjet) under ambient conditions enabled fast perovskite crystallization (<1 min) on PET. Full stacks with PEDOT and screen-printed carbon reached >10% efficiency in small areas, with minimal loss in 5 cm² modules.
In WP2, early stability testing showed improved results with refined encapsulation. Devices stored in nitrogen retained 60% of initial PCE after 1000 hours; minimodules kept 80% outdoors after 10 days. Impedance spectroscopy, PLQY, and ideality factor analysis were implemented to monitor degradation. Guanidinium and acetamidinium doping enhanced photoluminescence recovery under damage. Encapsulation using parylene and dual-layer acrylate/PDMS demonstrated good Pb containment.
In WP3, PILs and green solvents enabled removal of perovskite and carbon layers. PbI2, Cs⁺, FA⁺, and Au were recovered; gold purification is being refined. Cation exchange resins showed success in capturing Pb. Toxicity monitoring was initiated, and SSbD templates shared. Inventories for LCA, LCC, and SLCA were compiled.
HEPAFLEX advanced the feasibility of flexible perovskite PVs in materials synthesis, scalable processing, and environmental safety. Rapid, low-temperature fabrication via FIRA produced stable films. SAMs and PDI layers offer novel interface strategies, with SAMs enhancing stability and PDI layers representing greener ETL options. Green precursor synthesis and PILs reduce reliance on hazardous solvents, supporting circular design.
Scalable device fabrication was demonstrated with low-temperature, ambient-condition techniques and efficient PEDOT-based stacks. Advanced diagnostic tools now enable real-time monitoring of degradation. Self-healing effects in guanidinium/acamidinium-doped films suggest improved resilience. These results position HEPAFLEX as a driver of scalable, sustainable PV innovation.
Scalable device fabrication was demonstrated with low-temperature, ambient-condition techniques and efficient PEDOT-based stacks. Advanced diagnostic tools now enable real-time monitoring of degradation. Self-healing effects in guanidinium/acamidinium-doped films suggest improved resilience. These results position HEPAFLEX as a driver of scalable, sustainable PV innovation.