Perovskite materials - Page 3

This is a sponsored post by KYOCERA Document Solutions Inc. 

Kyocera Document Solutions has expanded its lineup of hole transport materials (HTMs) for perovskite solar cells, now offering SpiroOMeTAD and PTAA, and has begun research and development of novel HTMs. 

Leveraging proprietary molecular design technologies for organic materials, it has developed and manufactured HTMs such as SpiroOMeTAD and PTAA using optimized production methods that ensure high quality and lot-to-lot consistency. These compounds have successfully completed pilot production at the kilogram scale and are now available for stable, cost-effective supply.

Researchers at Chalmers University of Technology and the University of Birmingham have used advanced machine learning-driven molecular dynamics simulations to elucidate the low-temperature phase of formamidinium lead iodide (FAPbI₃).

Their study identifies the detailed crystal structure and octahedral tilt pattern characteristic of this phase and reveals that the rotational dynamics of formamidinium (FA) cations become arrested in a metastable configuration upon cooling. This cation freezing explains the persistent experimental challenges in accessing the thermodynamic ground state of FAPbI₃.

In the world of materials science, defects are usually seen as problems, unwanted microscopic features that
degrade performance, reduce efficiency, or shorten the life span of devices. But a recent study by scientists from Łukasiewicz Research Network – PORT Polish Centre for Technology Development and Indian Institute of Technology Kharagpur has challenged this perception.

The study showed that a specific structural "flaw" in crystals, known as the Ruddlesden-Popper (RP) fault, could actually be key to developing brighter and more robust light-emitting materials. The research focuses on perovskites, valued for their efficient charge transport and light-conversion capabilities. However, like all crystals, they are not flawless. Among their structural irregularities, RP faults, misalignments in atomic layer stacking, have traditionally been viewed as detrimental.

Researchers from Peking University have used artificial intelligence to accelerate the discovery of high-performance halide perovskite materials for photovoltaics. 

Their recent study introduces a machine learning (ML) model that accurately predicts bandgap, conduction band minimum (CBM), and valence band maximum (VBM) - critical electronic parameters determining solar cell efficiency and performance. The research directly addresses a key bottleneck in perovskite PV development: the need for faster, cost-effective identification of stable, lead-free, and high-efficiency materials. 

An international collaboration that includes researchers from UNSW, University of Cambridge, Colorado State University, Imperial College London, ANSTO Sydney and synchrotron facilities in Australia, the UK, and Germany recently found that dynamic nanodomains within lead halide perovskites could be vital for boosting their efficiency and stability. 

The team examined the nature of these microscopic structures, and how they impact the way electrons are energized by light and transported through the material, offering insights into more efficient solar cells.

Researchers at Imperial College London have examined the influence of light and oxygen on the stability of CH₃NH₃PbI₃ perovskite-based photoactive layers. They discovered why the cells degrade so quickly, and suggested a mechanism for slowing the decline. 

Until now, researchers believed that water played a dominant role in breaking down the cells, but Dr. Saif Haque and colleagues from the Department of Chemistry at Imperial College London have discovered that cells degrade even in dry air by the action of oxygen and light.

University of Utah researchers recently used temperature-dependent absorption and emission spectroscopy, as well as X-ray diffraction, to study the phase transition behaviors of Ruddlesden-Popper (RP) metal-halide hybrid perovskites. RP perovskites are a type of layered material made from alternating sheets of inorganic and organic components. These materials are potentially ideal for several applications, including light-emitting diodes (LEDs), thermal energy storage and solar-panel technology. 

Image from: Matter

A phase transition is a discrete change from one state of matter to another (such as ice to liquid water). Some substances, including water and perovskites, have multiple solid states with different properties. The U of Utah team demonstrated a connection between phase transitions and the material’s emissive properties. This introduces a form of dynamic control, or tunability, that offers multiple benefits for technological applications. Specifically, because perovskites contain both organic and inorganic components, the organic layers undergo phase transitions that influence the structure of the inorganic layers. The interplay of the organic and inorganic layers drastically alters the material’s properties.

Tokyo Chemical Industry (TCI), a global supplier of laboratory chemicals and specialty materials, has recently started to offer a new material for perovskite solar panel makers, Thiomorpholine hydroiodide (SMORI, 1) a passivation reagent suitable for p-i-n type perovskite solar cells.

TCI explains that n-i-p perovskite solar panels suffer from structural defects on the layer surface, and these can be fixed with a process called passivation. This process not only repairs the defects, but it also improves the solar panels' resistance to external degradation factors such as heat and moisture. With p-i-n type perovskites, normal passivation materials cause electron blocking. TCI's new SMORI material is useful for p-i-n panel passivation, thus enhancing the performance and stability of the panels.

SMORI, 1 (Thiomorpholine hydroiodide) is an ammonium salt that is suitable for p-i-n passivation. TCI explains that after deposition and annealing of the SMORI material onto the perovskite layer, a quasi-2D perovskite layer is formed, which is advantageous to the high durability of the perovskite layer. Compared to an untreated perovskite layer, the layer treated with the SMORI material has a conduction band energy level closer to the LUMO of the electron transport layer, which allows for smooth electron transfer.

Tokyo Chemical Industry (TCI), a global supplier of laboratory chemicals and specialty materials, has started offering n-Type SAM forming agents. These materials can be used to increase the efficiency of perovskite solar panels.

TCI says that these new PANDI materials can be used as an alternative to electron transport layers (ETLs) such as TiO2 and SnO2.  TCI's PANDI materials offer several advantages to perovskite n-i-p type devices:

• The highest level of conversion efficiency using n-type SAMs
• Uniform covering on metal oxide surfaces
• Enables device fabrication by low temperature process, which allows the deposition of the solar device on flexible plastic substrates
• The simultaneous reduction of optical reflectance and interfacial energetic losses

Canon has developed a new high-performance material that addresses two issues of perovskite solar cells: photoelectric conversion efficiency and longevity. This new material can, according to Canon, do two things: prevent the halogen ion movement that causes the perovskite layer to deteriorate, and move the charge generated in the perovskite layer.

A real-world demonstration (through joint research with Toin University of Yokohama) has reportedly showed that when this newly developed material is applied between the perovskite and HTL layers to form a new layer, it can maintain a high rate of photo-electric conversion efficiency while increasing durability. The new layer covers the bumps in the perovskite layer, creating a smoother surface that enables the stable mass production of the perovskite solar cell. As it also improves durability, the burden of maintenance and repair is also reduced.