Technical / research - Page 4

Researchers at China's Hangzhou Dianzi University have modified the absorber of a conventional perovskite solar cell with potassium trifluoromethanesulfonate (KTFS) and found that the additive improved the device's performance and stability. The cell’s perovskite film reportedly showed less lead defects and lower J-V hysteresis.

“The KTFS molecule is a typical kind of potassium salt including the cationic potassium (K⁺) and anionic trifluoromethanesulfonate (SO3CF3−), indicating a bifunctional interaction between KTFS and perovskite,” the team explained. “The sulfonyl group can passivate the undercoordinated lead of the deep-level defect and thus inhibit the non-radiative recombination.”

Researchers from Purdue University and ShanghaiTech University have developed a patent-pending method to synthesize high-quality, layered perovskite nanowires with large aspect ratios and tunable organic-inorganic chemical compositions.

The novel method creates layered perovskite nanowires with exceptionally well-defined and flexible cavities that exhibit a wide range of unusual optical properties beyond conventional perovskites.

Researchers at City University of Hong Kong (CityU) have presented a novel material design strategy and simple device-manufacturing process for skin-conformable perovskite-based alternating-current electroluminescent (PeACEL) devices. 

Working mechanism of the PeACEL device. Image credit: Nature Photonics

These devices exhibit a narrow emission bandwidth (full-width at half-maximum, <37 nm), continuously tunable emission wavelength (468–694 nm), high stretchability (400%) and adequate luminance (>200 cd m−2). 

Researchers at CHOSE (Centre for Hybrid and Organic Solar Energy) at University of Rome ‘‘Tor Vergata’’ and Solertix (affiliated with Italy-based solar manufacturer FuturaSun) have reported reduced yield losses in cell-to-module scaling by utilizing ultranarrow interconnection of 19.5 μm. 

In addition, the proposed interconnection technique may be used to achieve a 30% efficiency in area-matched 4T tandem designs featuring a perovskite module over a silicon cell.

Researchers from Friedrich-Alexander-University Erlangen-Nuremberg (FAU) and Helmholtz Institute Erlangen-Nürnberg for Renewable Energies (HI ERN) have developed a new recycling method for MAPbI₃ perovskite solar cells that uses a layer-by-layer solvent extraction technique. This process has shown the potential to recycle up to 99.97% of the material, aiming to reduce waste and conserve resources. 

The technique involves separating each layer of the solar cell, followed by processes to purify or modify the materials so they can be reused.

Researchers from Gwangju Institute of Science and Technology (GIST) and Institute for Basic Science (IBS) have developed a perovskite-based camera, inspired by the structures and functions of birds' eyes, specializing in object detection. 

Schematic illustration showing the visual ecology of birds. Image from Science Robotics

The eyes of different organisms in the natural world have evolved and been optimized to suit their habitat and the environment in which they survive. As a result of countless years of evolutionary adaptation to the environment of living and flying at high altitudes, bird eyes also have unique structures and visual functions. In the retina of an animal's eye, there is a small pit called the fovea that refracts the light entering the eye. Unlike the shallow foveae found in human eyes, bird eyes have deep central foveae, which refract the incoming light to a large extent. The region of the highest cone density lies within the foveae, allowing the birds to clearly perceive distant objects through magnification. This specialized vision is known as foveated vision.

Protonic ceramic fuel cells (PCFCs) have attracted much attention lately. These devices do not operate via the conduction of oxide ions (O²⁻) but light protons (H⁺) with smaller valence. A key feature of PCFCs is their ability to function at low and intermediate temperatures in the range of 50–500 °C. However, PCFCs based on perovskite electrolytes reported thus far suffer from low proton conductivity at low and intermediate temperatures.

A research team, led by Professor Masamoto Yashima from Tokyo Institute of Technology (Tokyo Tech), in collaboration with High Energy Accelerator Research Organization (KEK), has set out to address this limitation of perovskite-based proton conductors. 

Researchers from China's Ningbo University and Chinese Academy of Sciences (CAS) have developed a universal thermal reduction method to convert spent cobalt-based perovskites into high-performance bifunctional oxygen catalysts for zinc-air batteries (ZABs), achieving high-efficient Cobalt (Co) recovery and re-utilization. 

Cobalt is widely used in energy storage and conversion devices, although its content on our planet is not sufficient. Therefore, recycling it from spent Co-enriched materials is very valuable. Co-based perovskites, which contain abundant Co, are extensively utilized in solid oxide fuel cells, three-way catalysts, and oxygen-permeable membranes, and the recovery of Co from the spent Co-based perovskites is necessary to meet the long-term requirement of Co.

Researchers at the Chinese Academy of Sciences (CAS), in collaboration with Japan's Yamagata University, developed three isomeric bisphosphonate-anchored self-assembled molecules (SAMs) to achieve highly efficient and stable inverted perovskite solar cells (PSCs).

The wettability, absorbability and compactness of SAMs, which are used as hole-transporting layers (HTLs) for PSCs, critically affect the efficiency and stability of the devices. Therefore, the researchers proposed a molecular strategy to synthesize three bisphosphonate-anchored indolocarbazole (IDCz)-derived SAMs, namely IDCz-1, IDCz-2, and IDCz-3. The three SAMs with different positions of the two nitrogen atoms in the IDCz unit were each employed on conductive oxide substrates for inverted PSCs.

Researchers from China's Southwest Petroleum University, Beijing Institute of Technology, Chongqing University, National Center for Nanoscience and Technology and Tongwei Solar have designed a perovskite solar cell with remarkable perovskite film quality through the 'self-disintegrating seed' strategy. The device achieved both an impressive fill factor values and remarkable stability.

The researchers, in fact, report what they say is one of the highest fill factor values ever achieved for a perovskite solar cell, by reducing its nonradiative recombination and residual stress through what they called a self-disintegrating seed strategy.