Machine learning & AI
A unique material, nickel oxide demonstrates the ability to learn things about its environment in a way that emulates the most basic learning abilities of animals, as my colleagues and I describe in a new paper.
Dec 22, 2021
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54
Energy & Green Tech
To discover materials for better batteries, researchers must wade through a vast field of candidates. New research demonstrates a machine learning technique that could more quickly surface ones with the most desirable properties.
Dec 9, 2021
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7
Energy & Green Tech
An electrode coating just one molecule thick can significantly enhance the performance of an organic photovoltaic cell, KAUST researchers have found. The coating outperforms the leading material currently used for this task ...
Jun 10, 2021
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7
Energy & Green Tech
Efficient separation and collection of photogenerated carriers through the formation of asymmetric electron and hole transport channels is one of the key issues for crystalline silicon (c-Si) solar cells and other types of ...
Sep 29, 2020
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4
Energy & Green Tech
NIMS has found for the first time that a voltage increase that occurs in lithium-air batteries when they are being charged—a major issue preventing their practical use—is strongly and positively correlated with the degree ...
Sep 17, 2020
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5
Energy & Green Tech
Crystalline silicon solar panels could be just as effective when incorporated into stretchy wearable electronics or flexible robot skin as they are when used as rigid rooftop panels. KAUST researchers have devised a way to ...
Dec 23, 2019
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7
Energy & Green Tech
The Biden administration is set to announce more than $80 million in funding Thursday in a push to produce more solar panels in the U.S., make solar energy available to more people, and pursue superior alternatives to the ...
Apr 20, 2023
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6
Crystallinity refers to the degree of structural order in a solid. In a crystal, the atoms or molecules are arranged in a regular, periodic manner. The degree of crystallinity has a big influence on hardness, density, transparency and diffusion. In a gas, the relative positions of the atoms or molecules are completely random. Amorphous materials, such as liquids and glasses, represent an intermediate case, having order over short distances (a few atomic or molecular spacings) but not over longer distances.
Many materials (such as glass-ceramics and some polymers), can be prepared in such a way as to produce a mixture of crystalline and amorphous regions. In such cases, crystallinity is usually specified as a percentage of the volume of the material that is crystalline. Even within materials that are completely crystalline, however, the degree of structural perfection can vary. For instance, most metallic alloys are crystalline, but they usually comprise many independent crystalline regions (grains or crystallites) in various orientations separated by grain boundaries; furthermore, they contain other defects (notably dislocations) that reduce the degree of structural perfection. The most highly perfect crystals are silicon boules produced for semiconductor electronics; these are large single crystals (so they have no grain boundaries), are nearly free of dislocations, and have precisely controlled concentrations of defect atoms.
Crystallinity can be measured using x-ray diffraction, but calorimetric techniques are also commonly used.
This text uses material from Wikipedia, licensed under CC BY-SA
