Stability - Page 2

Researchers from Spain's UPV/EHU, ICIQ-BIST, CIDETEC and Mexico's Instituto Politécnico Nacional have explored the effect of chalcogen substitutions in fullerene derivatives to enhance efficiency and stability of perovskite solar cells.

The team examined the effects of chalcogen substitution in the chemical structure of phenyl-butyric acid methyl ester (PCBM) on the performance and stability of inverted perovskite solar cells (PSCs). PCBMs are the most widely used electron transport materials in inverted PSCs. However, these compounds can suffer from lack of stability under irradiation. In the race for optimizing the PCBM-like derivatives, the thiophene moiety has garnered significant attention for enhancing the performance and stability of PSCs. The novelty in this study relies on the tests done on the selenophene derivative. This compound was compared to thiophene and furan substituted derivatives, and to the reference PCBM without a chalcogenophene moiety, demonstrating a better surface passivation and reduced interfacial charge recombination.

Aiming to explore the potential of sulfur-based additives for increasing both device power conversion efficiency and moisture stability of perovskite solar cells, researchers from BCMaterials (Spain), Huazhong University of Science and Technology (China), Max Planck Institute for Polymer Research (Germany) and CNRS (France) have reported a mechanism for the local nanoscopic humidity ingression into a multifunctional additiviated formamidinium-loaded halide perovskites.

a) The molecular structure of additives used. Image from: Advanced Energy Materials

By tuning the iodide and bromide tails of the additives, the influence of sulfur heteroatom containing ammonium-amidinium salts on the photo-physical and device properties of a formamidinium-rich perovskite absorber was uncovered. 

Sofab Inks develops and produces advanced materials for perovskite solar cells. The company's flagship product is a solvent-based tin oxide ETL  that has already seen promising results in improving the performance and lifespan of perovskite solar cells. We interviewed the company's CEO Blake Martin and COO Jack Manzella, who help us understand the company's materials and business better. Click here to contact Sofab Inks to learn more or request a material sample.

Hello Blake and Jack. Earlier this year, Sofab Inks launched Tinfab, a high-performance and low-cost ETL material for perovskite solar cells. Can you detail the market reaction for your new material, and also the performance benefits that one can expect from this new ETL?

Since launching Tinfab, we’ve experienced significant interest across the industry, with approximately 40 companies and universities currently testing the material in perovskite solar cell applications. This strong engagement underscores the market's demand for innovative, scalable ETL solutions.

Tinfab is designed to fully replace C60/fullerenes in perovskite solar cells, addressing key limitations of C60, including lower stability, higher costs, and the complexity of vacuum deposition. Unlike C60, Tinfab can be solution-deposited in ambient environments, making it far more suitable for scalable manufacturing.

Researchers from Northwestern University, University of Toronto and Griffith University have developed a new protective coating that significantly extends the life of perovskite solar cells, making them more practical for real-world applications.

Typically, perovskite solar cells use an ammonium-based coating layer to enhance efficiency. While effective, ammonium-based layers degrade under environmental stress, including heat and moisture. The team has now developed a more robust layer — based on amidinium. In experiments, the new coating was 10 times more resistant to decomposition compared to conventional ammonium-based coatings. In addition, the amidinium-coated cells also tripled the cell’s T90 lifetime — the time it takes for a cell’s efficiency to drop 90% of its initial value when exposed to harsh conditions.

Researchers from the University of Oxford, University of Manchester,  University of Sheffield and Helmholtz-Zentrum Berlin (HZB) have developed a high volatility, low toxicity, biorenewable solvent system to fabricate a range of 2D perovskites, which can be used as effective precursor phases for subsequent transformation to α-formamidinium lead triiodide (α-FAPbI₃), fully processed under ambient conditions. 

This solvent system is meant to address challenges involved with producing perovskite solar cells (PSCs) via high-throughput coating methods, such as the use of harmful solvents, the expense of maintaining controlled atmospheric conditions, and the inherent instabilities of PSCs under operation. 

An international team of researchers, led by the University of Surrey with Imperial College London, recently reported a strategy to improve both the performance and stability for perovskite solar cells by mitigating a previously hidden degradation pathway.

In their new study, the scientists detail how they produced lead-tin perovskite solar cells that reach more than 23% power conversion efficiency (PCE) – which the team says is one of the best results achieved with this material and importantly, a design strategy which improves the lifetime of these devices by 66%. 

Chinese Academy of Sciences (CAS) researchers believe that the issue of instability of perovskite solar cells (PSCs) primarily originates from the migration of halide ions—particularly iodide ions (I⁻). Under light exposure and thermal stress, I⁻ migrates and transforms into I₂, leading to irreversible degradation and performance loss. 

To tackle this challenge, the team introduced the additive 2,1,3-benzothiadiazole,5,6-difluoro-4,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) (BT2F-2B) into the perovskite. The strong coordination between the unhybridized p orbital and lone-pair electrons from I⁻ inhibits the deprotonation of MAI/FAI and the subsequent conversion of I⁻ to I₂. The highly electronegative fluorine enhances its electrostatic interaction with I⁻. Consequently, the synergistic effect of BT2F-2B effectively suppresses the decomposition of perovskite and the defect density of the iodide vacancies. 

Researchers at Finland's Aalto University and Tampere University have developed an encapsulation method for perovskite solar cells (PSCs) to address both optical performance losses at the air-cell interface and intrinsic and extrinsic stability challenges. The team's one-step method provides PSCs with shielding from oxygen and moisture-induced degradation as well as in situ patterning for light management. 

In the new method, the entire surface and sides of the solar cells were coated with polydimethylsiloxane (PDMS), and the front-facing surface of the PSC was in situ–patterned using a soft lithography technique. A replica of leek leaf surface structures was created on the PDMS to reduce reflection and increase haze. The scientists explained that leek leaf replicas, previously used as add-on layers for PSC devices, have shown promise due to their optical and self-cleaning properties. 

Researchers from Ecole Polytechnique Fédérale de Lausanne (EPFL), North China Electric Power University, Westlake University, Lomonosov Moscow State University and others have described the addition of N,N-dimethylmethyleneiminium chloride ([Dmei]Cl) into perovskite precursor solutions to produce two cations in situ—namely 3-methyl-2,3,4,5-tetrahydro-1,3,5-triazin-1-ium ([MTTZ]⁺) and dimethylammonium ([DMA]⁺) cations - that enhanced the photovoltaic
performance and stability of perovskite solar modules.  

A schematic of the roles of [MTTZ]⁺ and [DMA]⁺ in the 3D perovskite matrix. Image from: Science

The team explained that the in situ formation of [MTTZ]⁺ cation increased the formation energy of iodine vacancies and enhanced the migration energy barrier of iodide and cesium ions, which suppressed nonradiative recombination, thermal decomposition, and phase segregation processes. 

Microquanta has reportedly achieved a conversion efficiency of 23.65% on small perovskite solar modules, certified by Fujian Metrology Institute.

The perovskite module has an area of 19.38 cm², achieved using its proprietary frozen laser repair technology. It is said to exhibit exceptional photo-thermal durability, with less than 5% efficiency degradation even after exposure to cumulative UV aging doses far exceeding the IEC 61215 standard (200 kWh).