Perovskite materials

Researchers at the Fujian Institute of Research on the Structure of Matter (FJIRSM), Chinese Academy of Sciences, have developed a two-dimensional perovskite antiferroelectric material, (2-MBA)₂CsPb₂Br₇ (2-MBA = 2-methylbutylammonium), with breakdown resistance and cycling stability among the highest reported for molecular antiferroelectrics.

Stable breakdown resistant molecular antiferroelectric triggered by confinement-dependent atomic displacement. (Image by FJIRSM)

Molecular antiferroelectrics, which arrange dipoles in antiparallel configurations between neighboring lattices, are attractive for high-precision digital displacement sensors and energy-storage capacitors. In practice, though, their usefulness has been limited by relatively low maximum applied field strength and poor long-term cycling stability, a gap the field has struggled to close because the atomic-level origin of antiferroelectric ordering itself has not been well understood.

Tokyo Chemical Industry (TCI), a global supplier of laboratory chemicals and specialty materials, is offering OA-TFSI (n-Octylammonium Bis(trifluoromethanesulfonyl)imide), an additive for the Spiro-OMeTAD hole transport layer in perovskite solar cells that provides both doping and passivation.

TCI explains that when OA-TFSI is added during the formation of the Spiro-OMeTAD hole transport layer, its two ions play different roles: the TFSI anion acts as a dopant for the hole transport material, while the n-octylammonium cation passivates the underlying perovskite layer. Compared to LiTFSI, the lithium salt commonly used as a Spiro-OMeTAD additive, OA-TFSI improves both the power conversion efficiency (PCE) and the stability of the device.

Researchers at ITMO University, the Kurchatov Institute's Institute of Macromolecular Compounds, and Harbin Institute of Technology have developed a solvothermal synthesis route for cesium lead halide (CsPbX₃, where X is chlorine, bromine, or iodine) perovskite nanostructures that gives precise control over both chemical composition and morphology, producing nanocrystals and nanoplatelets with tailored optical properties for optoelectronic and sensing applications.

Conventional methods for making perovskite nanocrystals, such as hot-injection and ligand-assisted reprecipitation, can produce high-quality emitters but tend to have narrow processing windows and fast, hard-to-control nucleation, making it difficult to reliably produce monodisperse one- or two-dimensional nanostructures at scale. Solvothermal synthesis, carried out at moderate temperatures of 100–200°C and elevated pressure inside sealed autoclaves, instead shifts crystal growth from a kinetically driven to a thermodynamically controlled process. The team used this approach as a multi-variable toolkit, adjusting reaction temperature, time, and precursor ratios to steer crystal growth along specific crystallographic facets.

Researchers at North Carolina State University, the University of North Carolina at Chapel Hill, Nanjing Normal University, Texas A&M University, Yale University, Shanghai Polytechnic University, and Wenzhou University have engineered a layered hybrid organic-inorganic perovskite (HOIP) thin film that combines one of the lowest thermal conductivities ever measured in a fully dense solid with mechanical rigidity that exceeds most plastics, foams, and aerogels.

Materials with very low thermal conductivity are valuable for thermal insulation and waste-heat management, from building envelopes to batteries and solar modules, but the best insulators - foams and aerogels - get their ultralow conductivity from porosity, which leaves them mechanically weak. Dense, rigid solids such as diamond conduct heat efficiently precisely because of the strong bonding that gives them their stiffness, so combining thermal insulation with mechanical rigidity in one dense material has been difficult. The team addressed that trade-off by engineering the organic cations in two-dimensional layered perovskites, which alternate rigid, crystalline inorganic lead-iodide layers with organic cation layers. 

Becquerel has signed a strategic cooperation agreement with Ximu Technology, an AI for Science (AI4S) solutions provider, to jointly develop high-efficiency, stable perovskite materials. The partnership combines AI4S methods with perovskite photovoltaic technology and is intended to explore broader applications of AI for materials discovery beyond solar cells as well.

Under the agreement, Ximu Technology will bring AI models, physics-based modeling, and data-computing capabilities to the collaboration, while Becquerel contributes its expertise in perovskite-crystalline silicon tandem cells. The stated goal is to accelerate material screening and device-performance optimization, with planned cooperation areas including AI-driven recommendations for new perovskite material candidates and high-throughput experimentation.

Researchers at the University of Moratuwa in Sri Lanka and the Sri Lanka Institute of Information Technology have built a machine-learning framework that screens oxide perovskites for band gaps suited to solar absorbers, narrowing a starting pool of over half a million candidate compositions down to 38 lead- and cadmium-free contenders worth further study.

Oxide perovskites are attractive for photovoltaics because their electronic and optical properties can be tuned through composition, but most known compositions are either insulating or have band gaps too wide for efficient light absorption. Identifying the minority with moderate, solar-relevant band gaps has traditionally meant either slow experimental trial and error or computationally expensive density functional theory (DFT) calculations, which become impractical once thousands of candidate compositions are involved.

Researchers at the University of Colorado Boulder's Renewable and Sustainable Energy Institute, led by Alex Zunger, working with the University of Sao Paulo, have shown that two simple structural measurements can predict how stable a halide perovskite alloy will be and what band gap it will have, without running a full quantum simulation for every composition.

Alloying is central to tuning perovskite light absorption and stability, but predicting which combinations of halogens, alkali metals and other elements will work has typically required slow, computationally expensive density-functional theory (DFT) calculations run one composition at a time. The team instead looked for structural descriptors that could stand in for those calculations. Running systematic DFT calculations across alloy families with substitutions at the halogen (X-site), alkali (A-site) and group-IV (B-site) positions, they found that the excess in cation-anion-cation (B-X-B') bond angles - a measure of how much the perovskite's octahedra are distorted - closely tracks the alloy's mixing enthalpy, an indicator of thermodynamic stability. Separately, the average cation-anion (B-X) bond length emerged as a reliable predictor of how the band gap shifts across the alloy series.

Tokyo Chemical Industry (TCI), a global supplier of laboratory chemicals and specialty materials, is offering TM-DHP, an additive that removes tin(IV) (Sn4+) impurities in tin-based perovskite solar cells.

TCI explains that tin-based perovskites are attractive as low-lead and lead-free alternatives for perovskite solar cells, but they suffer from a key drawback - the Sn2+ in the material readily oxidizes to Sn4+. These Sn4+ impurities act as defects that degrade the quality of the perovskite film and reduce device performance, so removing them is critical for fabricating efficient tin-based PSCs.

This is a sponsored post by KYOCERA Document Solutions Inc.

The performance of perovskite solar cells is not determined by the material itself alone. How we engineer the "buried interface" between the electrode and the perovskite at the molecular level can make a decisive difference—one that directly impacts charge extraction, reproducibility, and ultimately stability. Kyocera Document Solutions and the National Institute for Materials Science (NIMS) focused on the "number" and "arrangement" of methoxy groups introduced into self-assembled monolayers (SAMs). By elucidating how differences in molecular design—namely C21 versus C22—affect everything from work-function control to defect density, film formation, and device performance, the team presented design guidelines for SAMs in inverted (p–i–n) perovskite solar cells (PSCs).

The study, which focuses on methoxy-functionalized conjugated SAMs as hole-selective contacts, has been published in the international scientific journal ACS Applied Materials & Interfaces (DOI: 10.1021/acsami.6c04007).

Sunic System has announced that it will develop deposition equipment for perovskite-based displays, expanding its perovskite equipment business from solar cells into display applications. The company announced that it signed a memorandum of understanding (MOU) with SND Display for the commercialization of next-generation perovskite displays.

The partnership will focus on deposition technologies needed to apply perovskite materials to existing display manufacturing processes. The two companies plan to jointly develop deposition processes and equipment structures optimized for the material characteristics, as well as deposition precursor materials. The collaboration also includes joint technology testing, prototype verification, equipment and process cooperation for mass production, and research aimed at improving deposition uniformity and fine-patterning performance.