Color-Changing Signs (IMAGE)

New Retroreflective Material Could be Used in Nighttime Color-Changing Road Signs

BUFFALO, N.Y. -- A thin film that reflects light in intriguing ways could be used to make road signs that shine brightly and change color at night, according to a study that will be published on Aug. 9 in Science Advances.

by Staff Reporter

Photoluminescence and Electroluminsecence in Low-Dimensional and 3D Perovskite-Based Devices (IMAGE)

New Design Strategy Brightens Up The Future Of Perovskite-Based Light-Emitting Diodes

Scientists at the Tokyo Institute of Technology discovered a new strategy to design incredibly efficient perovskite-based LEDs with record-setting brightness by leveraging the quantum confinement effect.

by Staff Reporter

Energy Level Alignment in CsPbI3 (IMAGE)

New Perovskite Material Shows Early Promise as an Alternative to Silicon

Silicon dominates solar energy products -- it is stable, cheap, and efficient at turning sunlight into electricity. Any new material taking on silicon must compete, and win, on those grounds. As a result of international research collaboration, Shanghai Jiao Tong University, the Ecole Polytechnique Fédérale de Lausanne (EPFL), and the Okinawa Institute of Science and Technology Graduate University (OIST) have found a stable material that efficiently creates electricity -- which could challenge silicon hegemony. Writing in Science, the collaborating teams show how the material CsPbI3 has been stabilized in a new configuration capable of reaching high conversion efficiencies. CsPbI3 is an inorganic perovskite, a group of materials gaining popularity in the solar world due to their high efficiency and low cost. This configuration is noteworthy as stabilizing these materials has historically been a challenge. "We are pleased with results suggesting that CsPbI3 can compete with industry-leading materials," says Professor Yabing Qi, head of OIST's Energy Materials and Surface Sciences Unit, who led on the surface science aspect of the study. "From this preliminary result, we will now work on boosting the material's stability -- and commercial prospects." Energy level alignment CsPbI3 is often studied in its alpha phase, a well-known configuration of the crystal structure appropriately known as the dark phase because of its black color. This phase is particularly good at absorbing sunlight. Unfortunately, it is also unstable -- and the structure rapidly degrades into a yellowish form, less able to absorb sunlight. This study instead explored the crystal in its beta phase, a less well-known arrangement of the structure that is more stable than its alpha phase. While this structure is more stable, it shows relatively low power conversion efficiency. This low efficiency partly results from the cracks that often emerge in thin-film solar cells. These cracks induce the loss of electrons into adjacent layers in the solar cell -- electrons that can no longer flow as electricity. The team treated the material with a choline iodide solution to heal these cracks, and this solution also optimized the interface between layers in the solar cell, known as energy level alignment. "Electrons naturally flow to materials with lower potential energy for electrons, so it is important that the adjacent layers' energy levels are similar to CsPbI3," says Dr. Luis K. Ono, a co-author from Professor Qi's lab. "This synergy between layers results in fewer electrons being lost -- and more electricity being generated." The OIST team, supported by the OIST Technology Development and Innovation Center, used ultraviolet photoemission spectroscopy to investigate the energy level alignment between CsPbI3 and the adjacent layers. These data showed how electrons can then move freely through the different layers, generating electricity. The results showed a low loss of electrons to adjacent layers following treatment with choline iodide --due to better energy level alignments between the layers. By repairing the cracks that naturally emerge, this treatment led to an increase in conversion efficiency from 15% to 18%. While that leap may seem small, it brings CsPbI3 into the realm of certified efficiency, the competitive values offered by rival solar materials. Although this early result is promising, inorganic perovskite is still lagging. For CsPbI3 to truly compete with silicon, the team will next work on the trinity of factors allowing silicon's reign to continue -- stability, cost, and efficiency.

by Staff Reporter

Packet of Hydroxyl Radical Molecules Hitting a Liquid Surface (IMAGE)

Using Lasers to Visualize Molecular Mysteries in Our Atmosphere

WASHINGTON, D.C., August 6, 2019 -- Invisible to the human eye, molecular interactions between gases and liquids underpin much of our lives, including the absorption of oxygen molecules into our lungs, many industrial processes and the conversion of organic compounds within our atmosphere. But difficulties in measuring gas-liquid collisions have so far prevented the fundamental exploration of these processes. Kenneth McKendrick and Matthew Costen, both at Heriot-Watt University, in Edinburgh, U.K., hope their new technique of enabling the visualization of gas molecules bouncing off a liquid surface will help climate scientists improve their predictive atmospheric models. The technique is described in The Journal of Chemical Physics, from AIP Publishing. "The molecule of interest in our study, the hydroxyl radical, is an unstable fragment of a molecule that affects the whole of the understanding of atmospheric chemistry and things that genuinely affect climate," said McKendrick. "Some of these important OH reactions take place at the surface of liquid droplets, but we can't see surface interactions directly, so we measure the characteristics of the scattered molecules from real-time movies to infer what happened during their encounter with the liquid." Laser sheets are the key to the technique, inducing a short-lived fluorescent signal from each molecule as it passes through 10 nanosecond pulses. Laser-induced fluorescence isn't new in itself, but this was the first time laser sheets have been applied to scattering from a surface in a vacuum with no other molecules present to interfere with the scattering from the molecular beam. This enabled the McKendrick team to capture individual frames of molecular movement, from molecular beam to liquid surface and scattering, which were compiled into movies. Unlike previous methods of capturing gas-liquid interactions, all the characteristics needed to understand the interaction -- speed, scatter angle, rotation, etc. -- are captured within the simple movies that McKendrick describes as "intuitive." By observing the molecular film strips, McKendrick's team noted molecules scattered at a broad range of angles, similar to a ball bouncing off in all directions when thrown onto an uneven surface. This simple observation directly proved the surface of liquids is not flat. "When you get down to the molecular level, the surface of these liquids is very rough, so much so that you can barely tell the difference between the distribution of molecules when directed down vertically onto the surface or when at an angle of 45 degrees. This finding is important for understanding the chances of different molecular processes happening at the liquid surface," said McKendrick. As they improve their technique, McKendrick's team hopes to collect more refined information from atmospheric relevant liquids. But McKendrick points out the technique is not limited to the field of atmospheric science and is likely to soon be applied to understanding the gas-solid interactions that occur in processes such as the catalytic conversion of gases in car engines.

by Staff Reporter

Cover of ES&T (IMAGE)

New Process Discovered to Completely Degrade Flame Retardant in The Environment

A team of environmental scientists from the University of Massachusetts Amherst and China has for the first time used a dynamic, two-step process to completely degrade a common flame-retardant chemical, rendering the persistent global pollutant nontoxic.

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The FT-ICR MS Instrument Used in the Study (1 of 2) (IMAGE)

Record-Breaking Analytical Method for Fingerprinting Petroleum and Other Complex Mixtures

Scientists at the University of Warwick have developed a more powerful method of analyzing chemical mixtures, which has been able to assign a record-breaking number of 244,779 molecular compositions within a single sample of petroleum.

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Prashant Shenoy, University of Massachusetts at Amherst (IMAGE)

Researchers Develop Method to Automatically Estimate Rooftop Solar Potential

AMHERST, Mass. - Industry figures show the global rate of solar energy installations grew by 30 percent in one recent year, and the average cost of installing solar has fallen from $7 per watt to $2.8 per watt, making rooftop solar attractive to many more homeowners.

by Staff Reporter

Fertilizer Feast and Famine

Fertilizer Feast and Famine

Commercial organic and synthetic nitrogen fertilizer help feed around half of the world's population. While excessive fertilizer use poses environmental and public health risks, many developing nations lack access to it, leading to food insecurity, social unrest, and economic hardship.

by Staff Reporter

Sound Projector (IMAGE)

Researchers Create First-Ever Personalised Sound Projector With £10 Webcam

A University of Sussex research team has demonstrated the first sound projector that can track a moving individually and deliver an acoustic message as they move, to a high-profile tech and media conference in LA.

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Battery Production at Record Speed (IMAGE)

Battery Production at Record Speed

With a new coating process, researchers of Karlsruhe Institute of Technology (KIT) have produced electrodes for lithium-ion batteries at record speed. At the same time, the new process improves the quality of electrodes and reduces production costs.

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MASTAR Instrument (IMAGE)

NASA Team Builds CubeSat-Compatible Aerosol-Detecting Instrument

A NASA team has built a miniaturized instrument that will measure more comprehensively than existing instruments the specks of naturally occurring and manmade matter in the air that can adversely affect human health and the climate.

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Main Photo (IMAGE)

WPI Professor Teaming with Experts to Develop Wireless Sensors for New Prosthetics Device

Worcester, Mass. - July 29, 2019 - A Worcester Polytechnic Institute (WPI) professor, a local prosthetics company, and an occupational therapist with limb absence have teamed up to develop wireless sensors to improve the performance of prosthetics for individuals with upper limb amputations.

by Staff Reporter

LTPS, New Material Found by UCLouvain's Researchers (IMAGE)

A New Material for the Battery of the Future, Made in UCLouvain

Renewable sources of energy such as wind or photovoltaic are intermittent. The production peaks do not necessarily follow the demand peaks.

by Staff

Structure of a Blood Vessel (IMAGE)

A Study Demonstrates that p38 Protein Regulates the Formation of New Blood Vessels

A study performed at the Institute for Research in Biomedicine (IRB Barcelona) and published in the journal Nature Communications demonstrates that inhibition of the p38 protein boosts the formation of blood vessels in human and mice colon cancers. Known as angiogenesis, this process is critical in fuelling cancer cells, allowing them to grow and to eventually develop metastases.

by Staff

Gene Bank (IMAGE)

Embracing Bioinformatics in Gene Banks

The preservation of plant biodiversity is the task of the roughly 1,750 gene banks that are distributed around the world. So far, they store plant samples, and sometimes additional phenotypic or genetic information, of around 7,4 million accessions of plant species in total. It is expected that with the facilitated access to improved, quicker and cheaper sequencing and other omics technologies, the number of well-characterized accessions and the amount of detailed information that needs to be stored along with the biological material will be growing rapidly and continuously.

by Staff Reporter

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