Materials

Making Single-Source Precursors of Ternary Semiconductors

Commercially available reagents are used in a simplified synthesis. &A synthesis route has been developed for the commercial manufacture of single- source precursors of chalcopyrite semiconductor absorber layers of thin-film solar photovoltaic cells. The semiconductors in question are denoted by the general formula CuInxGa1–xSySe2–y, where 0≤x≤1 and 0≤y≤1.

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Norbornene-Based Polymer Electrolytes for Lithium Cells

These solid electrolytes are single-ion conductors. Norbornene-based polymers have shown promise as solid electrolytes for lithium-based rechargeable electrochemical cells. These polymers are characterized as single-ion conductors.

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Making Ternary Quantum Dots From Single-Source Precursors

Relative to a prior process, this process is simpler and safer. A process has been devised for making ternary (specifically, CuInS2) nanocrystals for use as quantum dots (QDs) in a contemplated next generation of highefficiency solar photovoltaic cells. The process parameters can be chosen to tailor the sizes (and, thus, the absorption and emission spectra) of the QDs.

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Spray CVD for Making Solar-Cell Absorber Layers

Spray CVD combines the advantages of metalorganic CVD and spray pyrolysis. Spray chemical vapor deposition (spray CVD) processes of a special type have been investigated for use in making CuInS2 absorber layers of thin-film solar photovoltaic cells from either of two subclasses of precursor compounds: [(PBu3) 2Cu(SEt)2In(SEt)2] or [(PPh3)2Cu(SEt)2 In(SEt)2] . CuInS2 is a member of the class of chalcopyrite semiconductors described in the immediately preceding article. [(PBu3)2Cu(SEt)2In(SEt)2] and [(PPh3)2 Cu(SEt)2In(SEt)2] are members of the class of single-source precursors also described in the preceding article.

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Improved Single-Source Precursors for Solar-Cell Absorbers

Deposition properties and final compositions can be tailored. Improved single-source precursor compounds have been invented for use in spray chemical vapor deposition (spray CVD) of chalcopyrite semiconductor absorber layers of thin-film solar photovoltaic cells. The semiconductors in question are denoted by the general formula CuInxGa1–xSySe2–y, where x≤1 and y≤2. These semiconductors have been investigated intensively for use in solar cells because they exhibit longterm stability and a high degree of tolerance of radiation, and their bandgaps correlate well with the maximum photon power density in the solar spectrum. In addition, through selection of the proportions of Ga versus In and S versus Se, the bandgap of CuInxGa1–xSySe2–y can be tailored to a value between 1.0 and 2.4 eV, thus making it possible to fabricate cells containing high and/or graded bandgaps.

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Glass/BNNT Composite for Sealing Solid Oxide Fuel Cells

Boron nitride nanotubes contribute to strength and fracture toughness. A material consisting of a barium calcium aluminosilicate glass reinforced with 4 weight percent of boron nitride nanotubes (BNNTs) has shown promise for use as a sealant in planar solid oxide fuel cells (SOFCs). The composition of the glass in question in mole percentages is 35BaO + 15CaO + 5Al2O3 + 10B2O3 + 35SiO2. The glass was formulated to have physical and chemical properties suitable for use as a planar- SOFC sealant, but has been found to be deficient in one aspect: it is susceptible to cracking during thermal cycling of the fuel cells. The goal in formulating the glass/BNNT composite material was to (1) retain the physical and chemical advantages that led to the prior selection of the barium calcium aluminosilicate glass as the sealant while (2) increasing strength and fracture toughness so as to reduce the tendency toward cracking.

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Separating Ethanol From Water Via Differential Miscibility

Alcohol for combustion could be purified more economically. The differential miscibility of castor oil in ethanol and water would be exploited to separate ethanol from water, according to a proposal. Burning the separated ethanol would produce more energy than would be consumed in the separation process. In contrast, the separation of a small amount of ethanol (actually an ethanol/water solution poor in ethanol) from water by the conventional process of distillation requires more energy than can be produced by burning the resulting distillate. As in the process described in the preceding article, "Separating Ethanol From Water Via Differential Solubility" (LAR-14894), the proposed alcohol/water separation process could be exploited industrially to produce clean fuel from fermented vegetable matter.

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