The absorbance or emission wavelength of composite materials comprising a transition metal doped shell disposed over a rare earth doped core and a functionalizable group on the surface of the transition metal doped shell can change upon subjection to a carboxylic acid. This method of changing the absorbance or emission wavelength of a composite material can be used to identify counterfeit currency using an ink comprising a composite material.

This disclosure provides systems, methods, and apparatus related to boron nitride nanomaterials. In one aspect, a method includes generating a directed flow of plasma. A boron-containing species is introduced to the directed flow of the plasma. Boron nitride nanostructures are formed in a chamber. In another aspect, a method includes generating a directed flow of plasma using nitrogen gas. A boron-containing species is introduced to the directed flow of the plasma. The boron-containing species can consist of boron powder, boron nitride powder, and/or boron oxide powder. Boron nitride nanostructures are formed in a chamber, with a pressure in the chamber being about 3 atmospheres or greater.

A process for etching a substrate comprising polycrystalline silicon to form silicon nanostructures includes depositing metal on top of the substrate and contacting the metallized substrate with an etchant aqueous solution comprising about 2 to about 49 weight percent HF and an oxidizing agent.

A device includes an upper metallic layer, a lower layer, and a memory array positioned between the upper and lower layers, wherein the memory electrical characteristic changes when storing data.

In order to provide a method for producing silver nanowires in which a local maximum of optical absorption in the plasmon absorption band can be shifted toward the short wavelength side without making the wire diameter smaller, a method for producing silver nanowires includes a step of heating a mixed liquid of a dispersion of silver nanowires and metal ions of a transition metal that is different from silver, and reducing the metal ions, thereby intermittently precipitating clumps of the transition metal on a surface of the silver nanowires. The thus produced silver nanowires have metal clumps intermittently along the length direction, and a local maximum of optical absorption in the plasmon absorption band of the silver nanowires has been shifted toward the short wavelength side.

A device includes an upper metallic layer, a lower layer, and a nano sensor array positioned between the upper and lower layers to detect a presence of a gas, a chemical, or a biological object, wherein each sensor's electrical characteristic changes when encountering the gas, chemical or biological object.

Methods of forming porous nano-scale or micro-scale structured materials and structured materials formed thereby. Such methods entail providing a donor material and reacting the donor material to form a compound that deposits on a surface of a substrate to produce nano-scale or micro-scale geometric features of the structured material. In particular embodiments, the donor material is in a solution and the reacting step is performed by contacting the surface of the substrate with the solution and directing heat through the solution onto the surface to locally heat a portion of the solution in contact therewith.

A semiconductor package structure is provided. The semiconductor package structure includes a chip structure. The semiconductor package structure includes a first conductive structure over the chip structure. The first conductive structure is electrically connected to the chip structure. The first conductive structure includes a first transition layer over the chip structure; a first conductive layer on the first transition layer; and a second conductive layer over the first conductive layer. The first conductive layer is substantially made of twinned copper. A first average roughness of a first top surface of the second conductive layer is less than a second average roughness of a second top surface of the first conductive layer.

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons. Related methods for use and manufacture of the same are also disclosed.

A semiconductor device includes a drain, a source, a gate electrode, and a nanowire between the source and drain. The nanowire has a first section with a first thickness and a second section with a second thickness greater than the first thickness. The second section is between the first section and at least one of the source or drain. The first nanowire includes a channel when a voltage is applied to the gate electrode.