Synthesis of Silver Nanowires with Reduced Diameters Using Benzoin-Derived Radicals to Make Transparent Conductors with High Transparency and Low Haze.

Reducing the diameter of silver nanowires has been proven to be an effective way to improve their optoelectronic performance by lessening light attenuation. The state-of-the-art silver nanowires are typically around 20 nm in diameter. Herein we report a modified polyol synthesis of silver nanowires with average diameters as thin as 13 nm and aspect ratios up to 3000. The success of this synthesis is based on the employment of benzoin-derived radicals in the polyol approach and does not require high-pressure conditions. The strong reducing power of radicals allows the reduction of silver precursors to occur at relatively low temperatures, wherein the lateral growth of silver nanowires is restrained because of efficient surface passivation. The optoelectronic performance of as-prepared 13 nm silver nanowires presents a sheet resistance of 28 Ω sq-1 at a transmittance of 95% with a haze factor of ∼1.2%, comparable to that of commercial indium tin oxide (ITO)

Synthesis of Silver Nanowires with Reduced Diameters Using Benzoin-Derived Radicals to Make Transparent Conductors with High Transparency and Low Haze.

Reducing the diameter of silver nanowires has been proven to be an effective way to improve their optoelectronic performance by lessening light attenuation. The state-of-the-art silver nanowires are typically around 20 nm in diameter. Herein we report a modified polyol synthesis of silver nanowires with average diameters as thin as 13 nm and aspect ratios up to 3000. The success of this synthesis is based on the employment of benzoin-derived radicals in the polyol approach and does not require high-pressure conditions. The strong reducing power of radicals allows the reduction of silver precursors to occur at relatively low temperatures, wherein the lateral growth of silver nanowires is restrained because of efficient surface passivation. The optoelectronic performance of as-prepared 13 nm silver nanowires presents a sheet resistance of 28 Ω sq-1 at a transmittance of 95% with a haze factor of ∼1.2%, comparable to that of commercial indium tin oxide (ITO)

Prospects for Employing Lithium Copper Phosphates as High-Voltage Li-Ion Cathodes

Three compositions of lithium copper phosphates: Li2CuPO4, Li2Cu5(PO4)4, and Li2CuP2O7have been studied as potential high-voltage cathode materials for Li-ion batteries, following computational predictions of high operating voltages. An assisted-microwave preparation of Li2CuPO4, which is otherwise difficult to prepare in nearly pure form, has been developed. The electrochemical performance of all three compounds has been investigated. The cyclability of these materials is found to be poor due to structural changes, irreversible reduction to metallic copper at potentials as high as 2.5 V, and the possibility of dissolution into the electrolyte. Some general understanding in regard to the use of Cu compounds in redox electrodes is presented

Prospects for Employing Lithium Copper Phosphates as High-Voltage Li-Ion Cathodes

Three compositions of lithium copper phosphates: Li2CuPO4, Li2Cu5(PO4)4, and Li2CuP2O7have been studied as potential high-voltage cathode materials for Li-ion batteries, following computational predictions of high operating voltages. An assisted-microwave preparation of Li2CuPO4, which is otherwise difficult to prepare in nearly pure form, has been developed. The electrochemical performance of all three compounds has been investigated. The cyclability of these materials is found to be poor due to structural changes, irreversible reduction to metallic copper at potentials as high as 2.5 V, and the possibility of dissolution into the electrolyte. Some general understanding in regard to the use of Cu compounds in redox electrodes is presented

Lead-free Cesium Europium Halide Perovskite Nanocrystals.

Because of the toxicity of lead, searching for a lead-free halide perovskite semiconducting material with comparable optical and electronic properties is of great interest. Rare-earth-based halide perovskite represents a promising class of materials for this purpose. In this work, we demonstrate the solution-phase synthesis of single-crystalline CsEuCl3 nanocrystals with a uniform size distribution centered around 15 nm. The CsEuCl3 nanocrystals have photoluminescence emission centered at 435 nm, with a full width at half-maximum of 19 nm. Furthermore, CsEuCl3 nanocrystals can be embedded in a polymer matrix that provides enhanced stability under continuous laser irradiation. Lead-free rare-earth cesium europium halide perovskite nanocrystals represent a promising candidate to replace lead halide perovskites

Lead-free Cesium Europium Halide Perovskite Nanocrystals.

Because of the toxicity of lead, searching for a lead-free halide perovskite semiconducting material with comparable optical and electronic properties is of great interest. Rare-earth-based halide perovskite represents a promising class of materials for this purpose. In this work, we demonstrate the solution-phase synthesis of single-crystalline CsEuCl3 nanocrystals with a uniform size distribution centered around 15 nm. The CsEuCl3 nanocrystals have photoluminescence emission centered at 435 nm, with a full width at half-maximum of 19 nm. Furthermore, CsEuCl3 nanocrystals can be embedded in a polymer matrix that provides enhanced stability under continuous laser irradiation. Lead-free rare-earth cesium europium halide perovskite nanocrystals represent a promising candidate to replace lead halide perovskites

Ligand-Free Processable Perovskite Semiconductor Ink.

Traditional covalent semiconductors require complex processing methods for device fabrication due to their high cohesive energies. Here, we develop a stable, ligand-free perovskite semiconductor ink that can be used to make patterned semiconductor-based optoelectronics in one step. The perovskite ink is formed via the dissolution of crystals of vacancy-ordered double perovskite Cs2TeX6 (X = Cl-, Br-, I-) in polar aprotic solvents, leading to the stabilization of isolated [TeX6]2- octahedral anions and free Cs+ cations without the presence of ligands. The stabilization of the fundamental perovskite ionic octahedral building blocks in solution creates multifunctional inks with the ability to reversibly transform between the liquid ink and the solid-state perovskite crystalline system in air within minutes. These easily processable inks can be patterned onto various materials via dropcasting, spraying or painting, and stamping, highlighting the crucial role of solvated octahedral complexes toward the rapid formation of phase-pure perovskite structures in ambient conditions

Ultrathin Epitaxial Cu@Au Core-Shell Nanowires for Stable Transparent Conductors.

Copper nanowire networks are considered a promising alternative to indium tin oxide as transparent conductors. The fast degradation of copper in ambient conditions, however, largely overshadows their practical applications. Here, we develop the synthesis of ultrathin Cu@Au core-shell nanowires using trioctylphosphine as a strong binding ligand to prevent galvanic replacement reactions. The epitaxial overgrowth of a gold shell with a few atomic layers on the surface of copper nanowires can greatly enhance their resistance to heat (80 °C), humidity (80%) and air for at least 700 h, while their optical and electrical performance remained similar to the original high-performance copper (e.g., sheet resistance 35 Ω sq-1 at transmittance of ∼89% with a haze factor <3%). The precise engineering of core-shell nanostructures demonstrated in this study offers huge potential to further explore the applications of copper nanowires in flexible and stretchable electronic and optoelectronic devices