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Results for “Grain”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The Effect of Annealing on the Grain Structure and Ionic Conductivity of Block Copolymer Electrolytes
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Entanglements via Slip Springs with Soft, Coarse-Grained Models for Systems Having Explicit Liquid–Vapor Interfaces
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Understanding the Copassivation Effect of Cl and Se for CdTe Grain Boundaries
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Tailoring of the Anti-Perovskite Solid Electrolytes at the Grain-Scale
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Coarse-Grained Modeling of Polymer Cleavage within a Porous Catalytic Support
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Coarse-Grained Water Model Development for Accurate Dynamics and Structure Prediction
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Impact of Photon Recycling, Grain Boundaries, and Nonlinear Recombination on Energy Transport in Semiconductors
Energy carrier transport and recombination in semiconductors can be directly monitored with optical microscopy, revealing key insights into fundamental photophysics and informs efficient optoelectronic device design. Oftentimes, energy transport is measured by monitoring a time-resolved expanding carrier profile after optical excitation under a focused laser beam. Although this approach has gained widespread adoption, the presence of competing dynamic processes, such as diffusion and photon recycling, has made it difficult to accurately extract and understand important semiconductor properties. Here, we develop and apply a new framework for modeling energy transport in both excitonic and free carrier semiconductors. Here, we demonstrate that processes such as nonlinear recombination and photon recycling can have a significant impact on the apparent energy carrier profiles, especially for excitonic materials with short radiative lifetimes. Additionally, we find that film microstructure can lead to unique transport profiles that strongly depends on material boundary behavior and the difference between feature size and diffusion length. Here, these findings provide a deeper understanding of energy transport in semiconducting materials and provide new strategies for the design and optimization of electronic and optoelectronic devices.
Dislocation exhaustion and ultra-hardening of nanograined metals by phase transformation at grain bo
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Sandwiching of MOF nanoparticles between graphene oxide nanosheets among ice grains
Current strategies to tailor the formation of nanoparticle clusters require specificity and directionality built into the surface functionalization of the nanoparticles by involved chemistries that can alter their properties. Here, we describe a non-disruptive approach to place nanomaterials of different shapes between nanosheets, i.e., nano-sandwiches, absent any pre-modification of the components. We demonstrate this with metal-organic frameworks (MOFs) and silicon oxide (SiO 2 ) nanoparticles sandwiched between graphene oxide (GO) nanosheets, MOF-GO and SiO 2 -GO, respectively. For the MOF-GO, the MOF shows significantly enhanced conductivity and retains its original crystallinity, even after one-year exposure to aqueous acid/base solutions, where the GO effectively encapsulates the MOF, shielding it from polar molecules and ions. The MOF-GOs are shown to effectively capture CO 2 from a high-humidity flue gas while fully maintaining their crystallinities and porosities. Similar behavior is found for other MOFs, including water-sensitive HKUST-1 and MOF-5, promoting the use of MOFs in practical applications. The nanoparticle sandwich strategy provides opportunities for materials science in the design of nanoparticle clusters consisting of different materials and shapes with predetermined spatial arrangements.
Accurate single-shot full-Stokes detection enabled by heterogeneous grain orientations in polycrystalline films
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Photo-enhanced ionic conductivity across grain boundaries in polycrystalline ceramics
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Facile route to bulk ultrafine-grain steels for high strength and ductility
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Intergranular fracture, grain-boundary structure, and dislocation-density interactions in FCC bicrystals
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