Emilie Planes

With power conversion efficiencies exceeding 27%, metal halide perovskite (PK) solar cells are among the most promising next‐generation photovoltaic technologies. Yet, their large‐scale deployment remains limited by instability under light, heat, and humidity. This study introduces a scalable stabilization strategy combining carbon‐based mesoscopic architectures based on MA _{1− x} (AVA) _x PbI ₃ perovskite and CsPbBr ₃ quantum dots (QDs) to simultaneously enhance durability and performance. All devices were fabricated under ambient conditions and evaluated following standardized ISOS protocols (ISOS‐D‐3, 85°C/85% RH; ISOS‐L‐1(SC), 1 SUN). Integrating QDs into the perovskite layer improved both spectral management and intrinsic stability, reducing degradation rates under damp‐heat and illumination stress. Devices incorporating short‐chain‐ligand QDs showed superior resistance to humidity and temperature, with performance losses below 5% after aging. Under continuous illumination, QD‐modified cells exhibited self‐healing behavior, recovering most of their initial efficiency after dark storage. Comparative analysis reveals that damp‐heat exposure induces irreversible chemical and interfacial degradation, whereas photo‐stress leads mainly to reversible interface effects mitigated by QDs. These results demonstrate the dual role of QDs in defect passivation and dynamic recovery, establishing a new framework for designing scalable, stable perovskite–QD heterostructures that meet industrial requirements for long‐term reliability.

Perovskite solar cells (PSCs) show great potential as a cost-effective, high-efficiency photovoltaic technology. Yet, their large-scale deployment is hindered by stability issues and the lack of sustainable end-of-life management. In this work, we introduce a simple yet highly effective recycling strategy that enables the recovery and reuse of both materials and substrates from degraded MAPbI3 electrodeposited devices, with a process fully performed under an ambient atmosphere. The process relies on selective delamination of the hole transport (HTL) and carbon electrode layers through controlled solvent immersion, preserving the integrity of the underlying ITO/c-TiO2/m-TiO2 stack. The degraded perovskite (PK), mainly composed of PbI2, is chemically regenerated into high-quality MAPbI3 and redeposited to form a fully functional recycled device that retains up to 75% of the initial photovoltaic performance. Beyond materials recovery, this study provides the first integrated technoeconomic and life-cycle assessment of a perovskite recycling route. Overall, the process preserves the ITO/c-TiO2/m-TiO2 stack, representing ∼75% of material cost at the lab scale and the majority of embodied impacts, thereby enabling high component retention during recycling. This combined experimental and analytical approach outlines a circular pathway for perovskite photovoltaics, bridging laboratory innovation with the broader goals of sustainable and resource-efficient solar technology development.

This study introduces a novel approach to fabricating large‐area perovskite active layers for carbon‐based perovskite solar cells (C‐PSCs) by leveraging electrodeposition, a low‐cost, scalable and yet underexplored processing route. The work focuses on the synthesis and comprehensive characterization of methylammonium lead iodide (MAPbI ₃ ) perovskites incorporating a low bismuth additive content (0.85 mol%), representing the first systematic investigation of bismuth‐assisted MAPbI ₃ films produced via electrodeposition. Despite the very low bismuth concentration, clear structure–property relationships were established by optimizing the conversion time, directly correlating processing conditions with optical, structural, and photovoltaic (PV) performance. A central innovation lies in the incorporation of bismuth, which not only modifies the perovskite crystallization but also markedly improves environmental stability. Long‐term aging tests under harsh conditions (90% RH, 30°C, 1000 h) revealed that these mixed perovskites maintain their microstructure and properties far better than MAPbI ₃ . The devices fabricated with perovskites containing 0.85% Bi retain up to 70% of their initial efficiency even without encapsulation, compared to only 35% for MAPbI ₃ ‐based controls. These results demonstrate the great potential of bismuth‐assisted electrodeposition for enabling durable, scalable perovskite PVs and offer a promising pathway toward sustainable C‐PSC manufacturing.

The spatiotemporal heterogeneities of ionic liquid electrolytes are probed through a combination of experimental and simulation-based methodologies.

Metal halide perovskites have reshaped the photovoltaic (PV) research, but their commercialization is hindered by limited stability and a spectral response confined to the visible range. This study explores the integration of CsPbBr₃ quantum dots (QDs) with MAPbI₃‐base perovskites as a strategy to convert ultraviolet light into visible light, thus enhancing both power conversion efficiency (PCE) and operational stability. Two types of QDs—one synthesized at room temperature with short‐chain ligands, the other commercially produced via hot injection with long‐chain ligands—are compared to assess the influence of synthesis route and surface chemistry on device performance. Heterojunction solar cells are fabricated by drop‐casting in ambient conditions, using a combination of QDs, MAPbI₃ and the AVAI additive. Various integration methods (blending into the perovskite matrix, sequential deposition, and surface application) are investigated. Devices incorporating QDs show a PCE improvement of up to 11.8%, reaching 10.4% compared to 9.3% for the reference. Thanks to advanced characterization techniques, these results offer valuable insights into how the properties of quantum dots influence charge generation mechanisms, paving the way for more robust and scalable carbon‐based perovskite solar cell technologies.

Developing perovskite solar cells (PSCs) under ambient conditions remains challenging due to the material's sensitivity to oxygen and moisture. This study presents two types of PSCs fabricated entirely under ambient atmospheric conditions using different deposition techniques: spin coating and drop casting. Spin‐coated cells were produced with a compact planar structure (C‐PSC), while drop‐cast cells utilized a mesoporous architecture (M‐PSC), which not only lowers manufacturing costs but also reduces the environmental impact by limiting perovskite exposure to air during processing. Both architectures employed a CH ₃ NH ₃ PbI ₃ perovskite layer, stabilized with either chloride anion (Cl ⁻ ) or ammonium valeric acid cation (AVA ⁺ ) additives to enhance film stability. The maturation process of fresh cells was also investigated, revealing that M‐PSC devices benefited from increased photovoltaic activity postmaturation. Functional cells were achieved, with the C‐PSC_Cl devices reaching nearly 13% power conversion efficiency (PCE) and M‐PSC_AVAI_m devices attaining a PCE of 10.7%. The M‐PSCs also showed larger active areas and more consistent performance, underscoring their reproducibility and suitability for scaling. This study provides valuable insights into cost‐effective and environmentally sustainable fabrication methods for PSCs, offering promising pathways for the large‐scale manufacturing and deployment of PSC technologies.

As perovskite photovoltaic devices can now compete with silicon technology in terms of efficiency, many strategies are investigated to improve their stability. In particular, degradation reactions can be hindered by appropriate device encapsulation, device architecture, and perovskite formulation. Mesoporous device architectures with a carbon electrode offer a plausible solution for the future commercialization of perovskite solar cells. They represent a low‐cost and stable solution with high potential for large‐scale production. Several studies have already demonstrated the potential of the mixed 2D/3D ammonium valeric acid iodide‐based MAPbI₃ formulation to increase the lifetime of pure MAPbI₃. They can however not describe the mechanisms responsible for the lifetime improvement. Using a full set of characterization techniques in the initial state and as a function of time during damp‐heat aging, new insights into the performance and degradation mechanisms may be observed. With (5‐AVA)_0.05MA_0.95PbI₃, the solar cells are very stable up to 3500 h and the degradation of performances essentially results from the loss of electrical contacts mainly located at the interfaces. In contrast, for the neat MAPbI₃, a poor stability is evidenced (T50 = 500 h) and the loss in performance results from the degradation of the bulk perovskite layer itself.