New research project on sustainable electronics promises to reduce e-waste problem
(Aarhus University) A new research project aims to tackle the ever-growing problem of electronic waste by merging materials science and printed electronics technology and creating novel electronically functional materials that are completely biologically degradable. The project is headed by Assistant Professor Shweta Agarwala from Aarhus University, Denmark, who's just received a grant of EUR 810.000 from the Villum Foundation. (Source: EurekAlert! - Biology)
Source: EurekAlert! - Biology - January 25, 2021 Category: Biology Source Type: news

Nanoscale localized contacts for high fill factors in polymer-passivated perovskite solar cells
Polymer passivation layers can improve the open-circuit voltage of perovskite solar cells when inserted at the perovskite–charge transport layer interfaces. Unfortunately, many such layers are poor conductors, leading to a trade-off between passivation quality (voltage) and series resistance (fill factor, FF). Here, we introduce a nanopatterned electron transport layer that overcomes this trade-off by modifying the spatial distribution of the passivation layer to form nanoscale localized charge transport pathways through an otherwise passivated interface, thereby providing both effective passivation and excellent cha...
Source: ScienceNOW - January 21, 2021 Category: Science Authors: Peng, J., Walter, D., Ren, Y., Tebyetekerwa, M., Wu, Y., Duong, T., Lin, Q., Li, J., Lu, T., Mahmud, M. A., Lem, O. L. C., Zhao, S., Liu, W., Liu, Y., Shen, H., Li, L., Kremer, F., Nguyen, H. T., Choi, D.-Y., Weber, K. J., Catchpole, K. R., White, T. P. Tags: Engineering, Materials Science reports Source Type: news

Ultrafast nanoimaging of the order parameter in a structural phase transition
Understanding microscopic processes in materials and devices that can be switched by light requires experimental access to dynamics on nanometer length and femtosecond time scales. Here, we introduce ultrafast dark-field electron microscopy to map the order parameter across a structural phase transition. We use ultrashort laser pulses to locally excite a 1T-TaS2 (1T-polytype of tantalum disulfide) thin film and image the transient state of the specimen by ultrashort electron pulses. A tailored dark-field aperture array allows us to track the evolution of charge-density wave domains in the material with simultaneous femtose...
Source: ScienceNOW - January 21, 2021 Category: Science Authors: Danz, T., Domröse, T., Ropers, C. Tags: Materials Science, Physics reports Source Type: news

Watching a phase transition unfold
(Source: ScienceNOW)
Source: ScienceNOW - January 21, 2021 Category: Science Authors: Stajic, J. Tags: Materials Science, Physics twis Source Type: news

Opening charge transport pathways
(Source: ScienceNOW)
Source: ScienceNOW - January 21, 2021 Category: Science Authors: Szuromi, P. Tags: Engineering, Materials Science twis Source Type: news

Thermopower and harvesting heat
(Source: ScienceNOW)
Source: ScienceNOW - January 21, 2021 Category: Science Authors: Shi, X., He, J. Tags: Materials Science, Physics perspective Source Type: news

Snapshots of a light-triggered transition
(Source: ScienceNOW)
Source: ScienceNOW - January 21, 2021 Category: Science Authors: Kogar, A. Tags: Materials Science, Physics perspective Source Type: news

Driving energetically unfavorable dehydrogenation dynamics with plasmonics
Nanoparticle surface structure and geometry generally dictate where chemical transformations occur, with higher chemical activity at sites with lower activation energies. Here, we show how optical excitation of plasmons enables spatially modified phase transformations, activating otherwise energetically unfavorable sites. We have designed a crossed-bar Au-PdHx antenna-reactor system that localizes electromagnetic enhancement away from the innately reactive PdHx nanorod tips. Using optically coupled in situ environmental transmission electron microscopy, we track the dehydrogenation of individual antenna-reactor pairs with ...
Source: ScienceNOW - January 14, 2021 Category: Science Authors: Sytwu, K., Vadai, M., Hayee, F., Angell, D. K., Dai, A., Dixon, J., Dionne, J. A. Tags: Materials Science, Physics reports Source Type: news

Coaxing unreactive sites
(Source: ScienceNOW)
Source: ScienceNOW - January 14, 2021 Category: Science Authors: Szuromi, P. Tags: Materials Science, Physics twis Source Type: news

Advanced materials in a snap
(DOE/Sandia National Laboratories) A research team at Sandia National Laboratories has successfully used machine learning -- computer algorithms that improve themselves by learning patterns in data -- to complete cumbersome materials science calculations more than 40,000 times faster than normal. (Source: EurekAlert! - Biology)
Source: EurekAlert! - Biology - January 5, 2021 Category: Biology Source Type: news

Why polyamide reverse-osmosis membranes work so well
(Source: ScienceNOW)
Source: ScienceNOW - December 31, 2020 Category: Science Authors: Geise, G. M. Tags: Engineering, Materials Science perspective Source Type: news

Stretching diamond to the limit
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Source: ScienceNOW - December 31, 2020 Category: Science Authors: Grocholski, B. Tags: Engineering, Materials Science twis Source Type: news

When two is better than four
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Source: ScienceNOW - December 31, 2020 Category: Science Authors: Lavine, M. S. Tags: Chemistry, Materials Science twis Source Type: news

Finding the path to better desalination
(Source: ScienceNOW)
Source: ScienceNOW - December 31, 2020 Category: Science Authors: Lavine, M. S. Tags: Engineering, Materials Science twis Source Type: news

A rechargeable zinc-air battery based on zinc peroxide chemistry
Rechargeable alkaline zinc-air batteries promise high energy density and safety but suffer from the sluggish 4 electron (e–)/oxygen (O2) chemistry that requires participation of water and from the electrochemical irreversibility originating from parasitic reactions caused by caustic electrolytes and atmospheric carbon dioxide. Here, we report a zinc-O2/zinc peroxide (ZnO2) chemistry that proceeds through a 2e–/O2 process in nonalkaline aqueous electrolytes, which enables highly reversible redox reactions in zinc-air batteries. This ZnO2 chemistry was made possible by a water-poor and zinc ion (Zn2+)–rich ...
Source: ScienceNOW - December 31, 2020 Category: Science Authors: Sun, W., Wang, F., Zhang, B., Zhang, M., Küpers, V., Ji, X., Theile, C., Bieker, P., Xu, K., Wang, C., Winter, M. Tags: Chemistry, Materials Science r-articles Source Type: news

Nanoscale control of internal inhomogeneity enhances water transport in desalination membranes
Biological membranes can achieve remarkably high permeabilities, while maintaining ideal selectivities, by relying on well-defined internal nanoscale structures in the form of membrane proteins. Here, we apply such design strategies to desalination membranes. A series of polyamide desalination membranes—which were synthesized in an industrial-scale manufacturing line and varied in processing conditions but retained similar chemical compositions—show increasing water permeability and active layer thickness with constant sodium chloride selectivity. Transmission electron microscopy measurements enabled us to dete...
Source: ScienceNOW - December 31, 2020 Category: Science Authors: Culp, T. E., Khara, B., Brickey, K. P., Geitner, M., Zimudzi, T. J., Wilbur, J. D., Jons, S. D., Roy, A., Paul, M., Ganapathysubramanian, B., Zydney, A. L., Kumar, M., Gomez, E. D. Tags: Engineering, Materials Science reports Source Type: news

Achieving large uniform tensile elasticity in microfabricated diamond
Diamond is not only the hardest material in nature, but is also an extreme electronic material with an ultrawide bandgap, exceptional carrier mobilities, and thermal conductivity. Straining diamond can push such extreme figures of merit for device applications. We microfabricated single-crystalline diamond bridge structures with ~1 micrometer length by ~100 nanometer width and achieved sample-wide uniform elastic strains under uniaxial tensile loading along the [100], [101], and [111] directions at room temperature. We also demonstrated deep elastic straining of diamond microbridge arrays. The ultralarge, highly controllab...
Source: ScienceNOW - December 31, 2020 Category: Science Authors: Dang, C., Chou, J.-P., Dai, B., Chou, C.-T., Yang, Y., Fan, R., Lin, W., Meng, F., Hu, A., Zhu, J., Han, J., Minor, A. M., Li, J., Lu, Y. Tags: Engineering, Materials Science reports Source Type: news

Relativistic kinematics of a magnetic soliton
A tenet of special relativity is that no particle can exceed the speed of light. In certain magnetic materials, the maximum magnon group velocity serves as an analogous relativistic limit for the speed of magnetic solitons. Here, we drive domain walls to this limit in a low-dissipation magnetic insulator using pure spin currents from the spin Hall effect. We achieve record current-driven velocities in excess of 4300 meters per second—within ~10% of the relativistic limit—and we observe key signatures of relativistic motion associated with Lorentz contraction, which leads to velocity saturation. The experimental...
Source: ScienceNOW - December 17, 2020 Category: Science Authors: Caretta, L., Oh, S.-H., Fakhrul, T., Lee, D.-K., Lee, B. H., Kim, S. K., Ross, C. A., Lee, K.-J., Beach, G. S. D. Tags: Materials Science, Physics reports Source Type: news

Magnetic special relativity
(Source: ScienceNOW)
Source: ScienceNOW - December 17, 2020 Category: Science Authors: Stajic, J. Tags: Materials Science, Physics twis Source Type: news

Making cheaper, biocompatible E-skin electrodes
(DGIST (Daegu Gyeongbuk Institute of Science and Technology)) DGIST materials scientists and colleagues in Korea have improved electrical conductivity in a polymer electrode for E-skin applications. Their approach is simple and cheap, but further enhancements are needed for the polymer to become a viable alternative to more expensive gold electrodes. The scientists published their findings in the journalBiosensors and Bioelectronics. (Source: EurekAlert! - Biology)
Source: EurekAlert! - Biology - December 10, 2020 Category: Biology Source Type: news

Efficiency from hole-selective contacts
(Source: ScienceNOW)
Source: ScienceNOW - December 10, 2020 Category: Science Authors: Szuromi, P. Tags: Engineering, Materials Science twis Source Type: news

Cracking the problem of cracking cathodes
(Source: ScienceNOW)
Source: ScienceNOW - December 10, 2020 Category: Science Authors: Lavine, M. S. Tags: Materials Science twis Source Type: news

Monolithic perovskite/silicon tandem solar cell with >29% efficiency by enhanced hole extraction
We report a monolithic perovskite/silicon tandem with a certified power conversion efficiency of 29.15%. The perovskite absorber, with a bandgap of 1.68 electron volts, remained phase-stable under illumination through a combination of fast hole extraction and minimized nonradiative recombination at the hole-selective interface. These features were made possible by a self-assembled, methyl-substituted carbazole monolayer as the hole-selective layer in the perovskite cell. The accelerated hole extraction was linked to a low ideality factor of 1.26 and single-junction fill factors of up to 84%, while enabling a tandem open-ci...
Source: ScienceNOW - December 10, 2020 Category: Science Authors: Al-Ashouri, A., Köhnen, E., Li, B., Magomedov, A., Hempel, H., Caprioglio, P., Marquez, J. A., Morales Vilches, A. B., Kasparavicius, E., Smith, J. A., Phung, N., Menzel, D., Grischek, M., Kegelmann, L., Skroblin, D., Gollwitzer, C., Malinauskas, Tags: Engineering, Materials Science r-articles Source Type: news

Reversible planar gliding and microcracking in a single-crystalline Ni-rich cathode
High-energy nickel (Ni)–rich cathode will play a key role in advanced lithium (Li)–ion batteries, but it suffers from moisture sensitivity, side reactions, and gas generation. Single-crystalline Ni-rich cathode has a great potential to address the challenges present in its polycrystalline counterpart by reducing phase boundaries and materials surfaces. However, synthesis of high-performance single-crystalline Ni-rich cathode is very challenging, notwithstanding a fundamental linkage between overpotential, microstructure, and electrochemical behaviors in single-crystalline Ni-rich cathodes. We observe reversible...
Source: ScienceNOW - December 10, 2020 Category: Science Authors: Bi, Y., Tao, J., Wu, Y., Li, L., Xu, Y., Hu, E., Wu, B., Hu, J., Wang, C., Zhang, J.-G., Qi, Y., Xiao, J. Tags: Materials Science reports Source Type: news

Hydrogels with fine-toothed molecular combs may make enduring glucose-monitoring implants
(Texas A&M University) In a new study, published online in the journal American Chemical Society (ACS) Applied Polymer Materials, scientists at Texas A&M University reported they have designed a hydrogel membrane that may be used to house optical glucose sensing materials, toward building a biosensor for monitoring sugar levels in diabetics. (Source: EurekAlert! - Medicine and Health)
Source: EurekAlert! - Medicine and Health - December 9, 2020 Category: International Medicine & Public Health Source Type: news

Formlabs Launches Permanent Crown Resin, Further Digitizing Restorative Dentistry
  Formlabs introduces Permanent Crown Resin, a cutting edge, lower cost alternative to chairside milling, and Soft Tissue Starter Pack to empower dentists to provide a better patient experience.Somerville, MA - December 8, 2020 ​ – F​ ormlabs​, a leading 3D printing company, today announced the expansion of its dental material offerings with the launch of ​Permanent Crown Resin​ and ​Soft Tissue Starter Pack​. The introduction of these new materials empowers dental offices and labs to further digitize resto rative dentistry and offer patients 3D printed long-term restorations such as fillings,...
Source: Dental Technology Blog - December 8, 2020 Category: Dentistry Source Type: news

John Mitchell obituary
My father, John Mitchell, who has died aged 75, was the founder of Carbohydrate Polymers, a scientific journal which grew from humble roots to become one of the publisher Elsevier ’s lead journals. John recognised the need for this much-needed outlet for research into polysaccharide science – the branch of food technology focused on the carbohydrates found most often in plants, algae and micro-organismsBorn in north London, the son of Albert Mitchell, who was in charge of general election campaigns for the Conservative party, and Marjorie (nee Woodcock), a homemaker, John attended the Haberdasher ’s Aske&...
Source: Guardian Unlimited Science - December 7, 2020 Category: Science Authors: Johanna Mitchell Tags: Food science Physics Publishing & drink industry Source Type: news

Probing the dark state
(Source: ScienceNOW)
Source: ScienceNOW - December 3, 2020 Category: Science Authors: Osborne, I. S. Tags: Materials Science, Physics twis Source Type: news

Directly visualizing the momentum-forbidden dark excitons and their dynamics in atomically thin semiconductors
Resolving momentum degrees of freedom of excitons, which are electron-hole pairs bound by the Coulomb attraction in a photoexcited semiconductor, has remained an elusive goal for decades. In atomically thin semiconductors, such a capability could probe the momentum-forbidden dark excitons, which critically affect proposed opto-electronic technologies but are not directly accessible using optical techniques. Here, we probed the momentum state of excitons in a tungsten diselenide monolayer by photoemitting their constituent electrons and resolving them in time, momentum, and energy. We obtained a direct visual of the momentu...
Source: ScienceNOW - December 3, 2020 Category: Science Authors: Madeo, J., Man, M. K. L., Sahoo, C., Campbell, M., Pareek, V., Wong, E. L., Al-Mahboob, A., Chan, N. S., Karmakar, A., Mariserla, B. M. K., Li, X., Heinz, T. F., Cao, T., Dani, K. M. Tags: Materials Science, Physics reports Source Type: news

Critical instability at moving keyhole tip generates porosity in laser melting
Laser powder bed fusion is a dominant metal 3D printing technology. However, porosity defects remain a challenge for fatigue-sensitive applications. Some porosity is associated with deep and narrow vapor depressions called keyholes, which occur under high-power, low–scan speed laser melting conditions. High-speed x-ray imaging enables operando observation of the detailed formation process of pores in Ti-6Al-4V caused by a critical instability at the keyhole tip. We found that the boundary of the keyhole porosity regime in power-velocity space is sharp and smooth, varying only slightly between the bare plate and powde...
Source: ScienceNOW - November 26, 2020 Category: Science Authors: Zhao, C., Parab, N. D., Li, X., Fezzaa, K., Tan, W., Rollett, A. D., Sun, T. Tags: Engineering, Materials Science reports Source Type: news

Driving the pores away
(Source: ScienceNOW)
Source: ScienceNOW - November 26, 2020 Category: Science Authors: Grocholski, B. Tags: Engineering, Materials Science twis Source Type: news

36 UCLA scientists among world ’s most influential researchers
Thirty-six UCLA scholars have been named as the world ’s most influential scientific researchers.Clarivate released its annual list of the most highly cited researchers, which includes dozens of UCLA scientists across various disciplines. The list is compiled by the Institute for Scientific Information at Clarivate using data based on scholarly publication counts and citation indexes. The selected researchers wrote publications that ranked in the top 1% by citations in their field for that year, according to the Web of Science citation index.TheUCLA Samueli School of Engineering hadeight faculty members named among t...
Source: UCLA Newsroom: Health Sciences - November 23, 2020 Category: Universities & Medical Training Source Type: news

37 UCLA scientists among world ’s most influential researchers
Editor ’s note: This story was changed on Nov. 24 to 37 UCLA scholars, after learning that Clarivate incorrectly identified a professor’s affiliation with their previous institution.Thirty-seven UCLA scholars have been named as the world ’s most influential scientific researchers.Clarivate released its annual list of the most highly cited researchers, which includes dozens of UCLA scientists across various disciplines. The list is compiled by the Institute for Scientific Information at Clarivate using data based on scholarly publication counts and citation indexes. The selected researchers wrote publicati...
Source: UCLA Newsroom: Health Sciences - November 23, 2020 Category: Universities & Medical Training Source Type: news

38 UCLA scientists among world ’s most influential researchers
This article was updated on Nov. 24 and again on Dec. 3 because Clarivate had incorrectly identified two of the researchers’ academic affiliations.Thirty-eight UCLA scholars have been named among the world ’s most influential scientific researchers.Clarivate released its annual list of the most highly cited researchers, which includes dozens of UCLA scientists across various disciplines. The list is compiled by the Institute for Scientific Information at Clarivate using data based on scholarly publication counts and citation indexes. The selected researchers wrote publications that ranked in the top 1% by citat...
Source: UCLA Newsroom: Health Sciences - November 23, 2020 Category: Universities & Medical Training Source Type: news

'Magic angle graphene's next trick: superconducting devices
(Source: ScienceNOW)
Source: ScienceNOW - November 19, 2020 Category: Science Authors: Wood, C. Tags: Physics, Applied, Materials Science In Depth Source Type: news

The more and less of electronic-skin sensors
(Source: ScienceNOW)
Source: ScienceNOW - November 19, 2020 Category: Science Authors: Liu, X. Tags: Materials Science perspective Source Type: news

Feeling temperature and touch
(Source: ScienceNOW)
Source: ScienceNOW - November 19, 2020 Category: Science Authors: Lavine, M. S. Tags: Physics, Applied, Materials Science twis Source Type: news

Artificial multimodal receptors based on ion relaxation dynamics
We present a deformable artificial multimodal ionic receptor that can differentiate thermal and mechanical information without signal interference. Two variables are derived from the analysis of the ion relaxation dynamics: the charge relaxation time as a strain-insensitive intrinsic variable to measure absolute temperature and the normalized capacitance as a temperature-insensitive extrinsic variable to measure strain. The artificial receptor with a simple electrode-electrolyte-electrode structure simultaneously detects temperature and strain by measuring the variables at only two measurement frequencies. The human skin&n...
Source: ScienceNOW - November 19, 2020 Category: Science Authors: You, I., Mackanic, D. G., Matsuhisa, N., Kang, J., Kwon, J., Beker, L., Mun, J., Suh, W., Kim, T. Y., Tok, J. B.- H., Bao, Z., Jeong, U. Tags: Physics, Applied, Materials Science reports Source Type: news

Locking in nanoscale strength
(Source: ScienceNOW)
Source: ScienceNOW - November 12, 2020 Category: Science Authors: Grocholski, B. Tags: Materials Science, Physics twis Source Type: news

Constrained minimal-interface structures in polycrystalline copper with extremely fine grains
Metals usually exist in the form of polycrystalline solids, which are thermodynamically unstable because of the presence of disordered grain boundaries. Grain boundaries tend to be eliminated through coarsening when heated or by transforming into metastable amorphous states when the grains are small enough. Through experiments and molecular dynamics simulations, we discovered a different type of metastable state for extremely fine-grained polycrystalline pure copper. After we reduced grain sizes to a few nanometers with straining, the grain boundaries in the polycrystals evolved into three-dimensional minimal-interface str...
Source: ScienceNOW - November 12, 2020 Category: Science Authors: Li, X. Y., Jin, Z. H., Zhou, X., Lu, K. Tags: Materials Science, Physics reports Source Type: news

Layering the charge
(Source: ScienceNOW)
Source: ScienceNOW - November 5, 2020 Category: Science Authors: Lavine, M. S. Tags: Chemistry, Materials Science twis Source Type: news

Rational design of layered oxide materials for sodium-ion batteries
Sodium-ion batteries have captured widespread attention for grid-scale energy storage owing to the natural abundance of sodium. The performance of such batteries is limited by available electrode materials, especially for sodium-ion layered oxides, motivating the exploration of high compositional diversity. How the composition determines the structural chemistry is decisive for the electrochemical performance but very challenging to predict, especially for complex compositions. We introduce the "cationic potential" that captures the key interactions of layered materials and makes it possible to predict the stacki...
Source: ScienceNOW - November 5, 2020 Category: Science Authors: Zhao, C., Wang, Q., Yao, Z., Wang, J., Sanchez-Lengeling, B., Ding, F., Qi, X., Lu, Y., Bai, X., Li, B., Li, H., Aspuru-Guzik, A., Huang, X., Delmas, C., Wagemaker, M., Chen, L., Hu, Y.-S. Tags: Chemistry, Materials Science reports Source Type: news

Speeding protons with metal vacancies
(Source: ScienceNOW)
Source: ScienceNOW - October 29, 2020 Category: Science Authors: Wang, F., He, J. Tags: Materials Science perspective Source Type: news

Lightening the load
(Source: ScienceNOW)
Source: ScienceNOW - October 29, 2020 Category: Science Authors: Yeston, J. Tags: Chemistry, Materials Science twis Source Type: news

Structural secrets of hybrid perovskites
(Source: ScienceNOW)
Source: ScienceNOW - October 29, 2020 Category: Science Authors: Szuromi, P. Tags: Materials Science, Physics twis Source Type: news

Vacancies enhance proton conductivity
(Source: ScienceNOW)
Source: ScienceNOW - October 29, 2020 Category: Science Authors: Lavine, M. S. Tags: Materials Science, Physics twis Source Type: news

Metal-organic magnets with large coercivity and ordering temperatures up to 242{degrees}C
Magnets derived from inorganic materials (e.g., oxides, rare-earth–based, and intermetallic compounds) are key components of modern technological applications. Despite considerable success in a broad range of applications, these inorganic magnets suffer several drawbacks, including energetically expensive fabrication, limited availability of certain constituent elements, high density, and poor scope for chemical tunability. A promising design strategy for next-generation magnets relies on the versatile coordination chemistry of abundant metal ions and inexpensive organic ligands. Following this approach, we report th...
Source: ScienceNOW - October 29, 2020 Category: Science Authors: Perlepe, P., Oyarzabal, I., Mailman, A., Yquel, M., Platunov, M., Dovgaliuk, I., Rouzieres, M., Negrier, P., Mondieig, D., Suturina, E. A., Dourges, M.-A., Bonhommeau, S., Musgrave, R. A., Pedersen, K. S., Chernyshov, D., Wilhelm, F., Rogalev, A., Mathoni Tags: Chemistry, Materials Science reports Source Type: news

CdPS3 nanosheets-based membrane with high proton conductivity enabled by Cd vacancies
We report a class of membranes assembled with two-dimensional transition-metal phosphorus trichalcogenide nanosheets, in which the transition-metal vacancies enable exceptionally high ion conductivity. A Cd0.85PS3Li0.15H0.15 membrane exhibits a proton conduction dominant conductivity of ~0.95 siemens per centimeter at 90° Celsius and 98% relative humidity. This performance mainly originates from the abundant proton donor centers, easy proton desorption, and excellent hydration of the membranes induced by cadmium vacancies. We also observed superhigh lithium ion conductivity in Cd0.85PS3Li0.3 and Mn0.77PS3Li0.46 membran...
Source: ScienceNOW - October 29, 2020 Category: Science Authors: Qian, X., Chen, L., Yin, L., Liu, Z., Pei, S., Li, F., Hou, G., Chen, S., Song, L., Thebo, K. H., Cheng, H.-M., Ren, W. Tags: Materials Science, Physics reports Source Type: news

Atomic-scale microstructure of metal halide perovskite
Hybrid organic-inorganic perovskites have high potential as materials for solar energy applications, but their microscopic properties are still not well understood. Atomic-resolution scanning transmission electron microscopy has provided invaluable insights for many crystalline solar cell materials, and we used this method to successfully image formamidinium lead triiodide [CH(NH2)2PbI3] thin films with a low dose of electron irradiation. Such images reveal a highly ordered atomic arrangement of sharp grain boundaries and coherent perovskite/PbI2 interfaces, with a striking absence of long-range disorder in the crystal. We...
Source: ScienceNOW - October 29, 2020 Category: Science Authors: Rothmann, M. U., Kim, J. S., Borchert, J., Lohmann, K. B., OLeary, C. M., Sheader, A. A., Clark, L., Snaith, H. J., Johnston, M. B., Nellist, P. D., Herz, L. M. Tags: Materials Science, Online Only, Physics r-articles Source Type: news

Design of higher valency in covalent organic frameworks
We report a strategy for making COFs with valency 8 (cubes) and "infinity" (rods). The linker 1,4-boronophenylphosphonic acid—designed to have boron and phosphorus as an isoelectronic combination of carbon-group elements—was condensed into a porous, polycubane structure (BP-COF-1) formulated as (–B4P4O12–)(–C6H4–)4. It was characterized by x-ray powder diffraction techniques, which revealed cubes linked with phenyls. The isoreticular forms (BP-COF-2 to 5) were similarly prepared and characterized. Large single crystals of a constitutionally isomeric COF (BP-COF-6), composed of ...
Source: ScienceNOW - October 22, 2020 Category: Science Authors: Gropp, C., Ma, T., Hanikel, N., Yaghi, O. M. Tags: Chemistry, Materials Science, Online Only r-articles Source Type: news