Perovskite materials - Page 8

A team from Israel's Technion Institute of Technology has announced the development of self-healing perovskite nanocrystals.

Having to frequently replace electronics due to malfunctioning of materials is unavoidable today, since every device suffers from degradation as a result of defects that accumulate during use over time. This generates, in addition to customer frustration and costs, a heavy environmental footprint.

Scientists at the National Renewable Energy Laboratory (NREL) have experimentally synthesized a nitride perovskite material that previously only existed in theory and measured its properties in collaboration with researchers at the Colorado School of Mines.

The new material could theoretically be used for microelectromechanical devices such as the ones used in telecommunications and other areas. Nitride perovskites have been computationally predicted to be stable, but not many have been synthesized, and their experimental properties remain largely unknown, the researchers explained in their new article.

Researchers from Queen Mary University of London, in collaboration with an international team of scientists, developed a new process for creating FAPbI₃.

One of the challenges with making FAPbI₃ is that the high temperatures (150°C) used can cause the crystals within the material to 'stretch', making them strained, which favors the yellow phase that isn't suitable for solar cells. While previous reports have used small amounts of additional chemicals/additives to help form FAPbI₃ under these conditions, it can be very hard to control the uniformity and amounts of these additives when making solar cells at a very large scale, and the long-term impact of including them is not yet known.

A project called NanoQI, funded by the European Union with Horizon 2020 funds, aims to develop an industry-ready, real-time and in-line capable method for characterizing and imaging nano-dimensions of (thin film) nanomaterials in the critical range of 1 to 300 nm on large sample surfaces of more than 500 × 500 mm². The project involves a consortium of eight companies and organizations from five European countries and was initiated on March 1, 2020. The project's mid-term was in September 2021.

HSI hardware integration and algorithms for automatic quality assessment using HSI, based on XRR/XRD- ground-truth data. (Image: Fraunhofer IWS)

NanoQI combines for the first time X-ray reflectometry (XRR) and X-ray diffraction analysis (XRD) as well as broadband hyperspectral imaging (HSI) into a fast, real-time method for quality control in thin film processing that can be directly integrated into the coating equipment. This combination enables equipment operators to access application-relevant properties such as the thickness of individual layers in a coating system, the solid state structure or even derived functional properties ' such as water vapor permeability ' while the coating is still in progress.

A research team at KTH Royal Institute of Technology has developed a synthetic alloy that increases perovskite cells' durability while preserving energy conversion performance.

'Perovskite usually dissolves immediately on contact with water,' says co-author James Gardner, a researcher at KTH. 'We have proven that our alloyed perovskite can survive for several minutes completely immersed in water, which is over a 100 times more stable than the perovskite alone. What's more, the solar cells that we have built from the material retain their efficiency for more than 100 days after they are manufactured.'

A recent study by Lawrence Berkeley National Laboratory (Berkeley Lab), Technische Universität München, EPFL and The Pennsylvania State University has found that solar materials manufacturing could be aided by a new instrument that uses two types of light ' invisible X-ray light and visible laser light ' to probe a perovskite material's crystal structure and optical properties as it is synthesized.

'When people make solar thin films, they typically have a dedicated synthesis lab and need to go to another lab to characterize it. With our development, you can fully synthesize and characterize a material at the same time, at the same place', said Carolin Sutter-Fella, a scientist at Berkeley Lab's Molecular Foundry.

Scientists at MIT recently reported creating the first high-quality thin films of a new family of semiconductor materials - chalcogenide perovskites. This achievement, lead by MIT researcher Rafael Jaramillo, has the potential to impact multiple fields of technology.

Chalcogenide perovskites could have applications in solar cells and lighting, Jaramillo says. He notes, however, that "the history of semiconductor research shows that new families of semiconductors are generally enabling in ways that are not predictable."

A team of researchers from HZB, CNRS and Charles University used a multi-method approach to quantify and characterize defects in single crystal MAPbI₃, giving a cross-checked overview of their properties. The team characterized five different defect types and measured the interaction between these defects and the charge carriers.

MAPI semiconductors consist of organic methylammonium cations and lead iodide octahedra that form a perovskite structure. MAPI based solar cells have achieved efficiencies of 25% within a few years. But so far, the semi-organic semiconductors are still ageing rapidly.

A team of researchers from Oak Ridge National Laboratory, Florida State University, Argonne National Laboratory, University of Pittsburgh, Pittsburgh Quantum Institute and Sungkyunkwan University has found a rare quantum material in which electrons move in coordinated ways, essentially 'dancing.'

Straining the material creates an electronic band structure that sets the stage for exotic, more tightly correlated behavior ' similar to tangoing ' among Dirac electrons, which are especially mobile electric charge carriers that may someday enable faster transistors.

Researchers from ITMO University, the Far Eastern Federal University (FEFU), the Image Processing Systems Institute of RAS, and Tokai University (Japan) have discovered a way to fashion perovskite microcrystals into desired shapes for further use in the production of lenses and other optoelectronic elements without loss of quality.

This research opens up new opportunities for the creation of micro-optical elements that could be used in microchips and other optoelectronic devices.