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Results for “crystalline”
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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Growth of Crystalline Bimetallic Metal–Organic Framework Films via Transmetalation
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Quasicrystals and Their Approximants in a Crystalline?Amorphous Diblock Copolymer
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Rheology of Smectic Liquid Crystalline Elastomers with Dynamic Covalent Bonds
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Direct Imaging of the Crystalline Domains and Their Orientation in the PS- b -PEO Block Copolymer with 4D-STEM
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Crystallinity-Independent Toughness in Renewable Poly( l -lactide) Triblock Plastics
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Thin Film Self-Assembly of a Silicon-Containing Rod−Coil Liquid Crystalline Block Copolymer
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Tacticity Effect on Mesogen-Free Liquid Crystalline Self-assembly Induced by Strong Dipole−Dipole Interactions
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Laser-Induced Crystalline-Phase Transformation for Hematite Nanorod Photoelectrochemical Cells
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Understanding the Catalytic Active Sites of Crystalline CoSb x O y for Electrochemical Chlorine Evolution
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Surfactant–Polymer Complexation and Competition on Drug Nanocrystal Surfaces Control Crystallinity
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Three-Dimensional Integration of Functional Oxides and Crystalline Silicon for Optical Neuromorphic Computing Using Nanometer-Scale Oxygen Scavenging Barriers
Dating to the first reports of epitaxial oxide deposition on Si(001), the integration of complex oxides on silicon has been a fast-moving area of research, where fundamental materials physics is intimately connected to tremendous technological promise in such areas as integrated electronics, optical neuromorphic and quantum computing, and sensing, to name a few. Despite their great promise, devices relying on the co-integration of silicon and epitaxial perovskites are typically limited to basic, planar geometries due to practical issues with their fabrication. In this paper, we overcome these long-standing challenges by developing a method to produce high-quality Si(001)/TMO/Si(001)/TMO heterostructures without wafer bonding, resulting in the straightforward three-dimensional integration of functional complex oxides and active Si(001) layers into a technologically relevant platform that is needed for on-chip hardware implementations of neuromorphic computing based on optical signals. We present detailed structural and chemical characterization of our heterostructures and discuss generalized design rules for their fabrication. Our results exponentially expand the universe of practically achievable TMO-based integrated devices and push this promising class of materials closer to realizing their full technological potential.
Chemical Passivation of Crystalline Si by Al 2 O 3 Deposited Using Atomic Layer Deposition: Implications for Solar Cells
The atomistic-level mechanism for the chemical passivation of the monocrystalline Si (c-Si) surface with thermally annealed Al 2 O 3 was studied using in situ infrared spectroscopy and photoconductance decay measurements. Al 2 O 3 was deposited on high-lifetime, float-zone c-Si substrates using atomic layer deposition (ALD) from trimethylaluminum (TMA), and H 2 O or O 3 . Surface-sensitive attenuated total reflection Fourier transform infrared spectroscopy was used to monitor the c-Si/Al 2 O 3 interface, as well as the bulk of the Al 2 O 3 film during the entire process. Our results show that some surface Si–H bonds are preserved after the ALD of Al 2 O 3 on H-terminated Si. During the annealing step at 400 °C, restructuring occurs at the c-Si/Al 2 O 3 interface to form interfacial SiO x . Isotope labeling was used to differentiate interfacial SiD bonds on the c-Si surface from H incorporated in Al 2 O 3 . Within the sensitivity of our infrared setup (~10 13 cm –2 ), we did not observe any net migration of atomic H or D from Al 2 O 3 to the c-Si/Al 2 O 3 interface. To isolate the effects of chemical and field-effect passivation of Al 2 O 3 thin films, we carried out surface passivation studies on c-Si/SiO 2 /Al 2 O 3 stacks. We also annealed these stacks in different atmospheres to test the influence of annealing atmospheres on the chemical passivation of c-Si by Al 2 O 3 and observed that O 2 -containing atmosphere led to the best surface chemical passivation.