Abstract: Provided is a method of using a nanowire diode with an array of more than 100 nanowires functionalized with binding agents that bind to one or more specific biomarkers, the nanowires being non-horizontally aligned on a substrate, and the nanowires being electrically connected to each other, to measure the presence or absence of the one or more specific biomarkers. The method comprises exposing the nanowires to a solution of interest, shining light with a wavelength between 350 nm and 700 nm on the nanowire diode, measuring electrical current that is optically induced in the nanowire diode by the light, and comparing the optically induced electrical current with and without the solution of interest present to deduce a concentration of the one or more specific biomarkers in the solution of interest.

Abstract: Provided is a sensor with nanowires in an aligned array. In one example, the heaviest doped region is not in the nanowire array, but in the bulk silicon substrate and the sensor is functionalized to be have modified electrical properties when proteins are present.

Abstract: 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.

Abstract: In an aspect of the disclosure, a process for forming nanostructuring on a silicon-containing substrate is provided. The process comprises (a) performing metal-assisted chemical etching on the substrate, (b) performing a clean, including partial or total removal of the metal used to assist the chemical etch, and (c) performing an isotropic or substantially isotropic chemical etch subsequently to the metal-assisted chemical etch of step (a). In an alternative aspect of the disclosure, the process comprises (a) performing metal-assisted chemical etching on the substrate, (b) cleaning the substrate, including removal of some or all of the assisting metal, and (c) performing a chemical etch which results in regularized openings in the silicon substrate.

Abstract: A process is provided for contacting a nanostructured surface. The process may include (a) providing a substrate having a nanostructured material on a surface, (b) passivating the surface on which the nanostructured material is located, (c) screen printing onto the nanostructured surface and (d) firing the screen printing ink at a high temperature. In some embodiments, the nanostructured material compromises silicon. In some embodiments, the nanostructured material includes silicon nanowires. In some embodiments, the nanowires are around 150 nm, 250 nm, or 400 nm in length. In some embodiments, the nanowires have a diameter range between about 30 nm and about 200 nm. In some embodiments, the nanowires are tapered such that the base is larger than the tip. In some embodiments, the nanowires are tapered at an angle of about 1 degree, about 3 degrees, or about 10 degrees. In some embodiments, a high temperature can be approximately 700 C, 750 C, 800 C, or 850 C.

Abstract: In an embodiment of the disclosure, a structure is provided which comprises a silicon substrate and a plurality of necklaces of silicon nanowires which are in direct physical contact with a surface of the silicon substrate, wherein the necklaces cover an area of the silicon substrate.

Abstract: In an aspect of the disclosure, a process for forming nanostructuring on a silicon-containing substrate is provided. The process comprises (a) performing metal-assisted chemical etching on the substrate, (b) performing a clean, including partial or total removal of the metal used to assist the chemical etch, and (c) performing an isotropic or substantially isotropic chemical etch subsequently to the metal-assisted chemical etch of step (a). In an alternative aspect of the disclosure, the process comprises (a) performing metal-assisted chemical etching on the substrate, (b) cleaning the substrate, including removal of some or all of the assisting metal, and (c) performing a chemical etch which results in regularized openings in the silicon substrate.

Abstract: 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.

Abstract: In an aspect of this disclosure, a method is provided comprising the steps of: (a) providing a silicon-containing substrate, (b) depositing a first metal on the substrate, (c) etching the substrate produced by step (b) using a first etch, and (d) etching the substrate produced by step (c) using a second etch, wherein the second etch is more aggressive towards the deposited metal than the first etch, wherein the result of step (d) comprises silicon nanowires. The method may further comprise, for example, steps (b1) subjecting the first metal to a treatment which causes it to agglomerate and (b2) depositing a second metal.

Abstract: A process is provided for contacting a nanostructured surface. The process may include (a) providing a substrate having a nanostructured material on a surface, (b) passivating the surface on which the nanostructured material is located, (c) screen printing onto the nanostructured surface and (d) firing the screen printing ink at a high temperature. In some embodiments, the nanostructured material compromises silicon. In some embodiments, the nanostructured material includes silicon nanowires. In some embodiments, the nanowires are around 150 nm, 250 nm, or 400 nm in length. In some embodiments, the nanowires have a diameter range between about 30 nm and about 200 nm. In some embodiments, the nanowires are tapered such that the base is larger than the tip. In some embodiments, the nanowires are tapered at an angle of about 1 degree, about 3 degrees, or about 10 degrees. In some embodiments, a high temperature can be approximately 700 C, 750 C, 800 C, or 850 C.

Abstract: A process is provided for contacting a nanostructured surface. In that process, a substrate is provided having a nanostructured material on a surface, the substrate being conductive and the nanostructured material being coated with an insulating material. A portion of the nanostructured material is at least partially removed. A conductor is deposited on the substrate in such a way that it is in electrical contact with the substrate through the area where the nanostructured material has been at least partially removed.

Abstract: In an aspect of this disclosure, a method is provided comprising the steps of: (a) providing a silicon-containing substrate, (b) depositing a first metal on the substrate, (c) etching the substrate produced by step (b) using a first etch, and (d) etching the substrate produced by step (c) using a second etch, wherein the second etch is more aggressive towards the deposited metal than the first etch, wherein the result of step (d) comprises silicon nanowires. The method may further comprise, for example, steps (b1) subjecting the first metal to a treatment which causes it to agglomerate and (b2) depositing a second metal.

Abstract: In an embodiment of the disclosure, a structure is provided which comprises a silicon substrate and a plurality of necklaces of silicon nanowires which are in direct physical contact with a surface of the silicon substrate, wherein the necklaces cover an area of the silicon substrate.

Abstract: A process is provided for etching a silicon-containing substrate to form nanowire arrays. In this process, one deposits nanoparticles and a metal film onto the substrate in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere. One submerges the metallized substrate into an etchant aqueous solution comprising HF and an oxidizing agent. In this way arrays of nanowires with controlled diameter and length are produced.

Abstract: Another aspect of the present disclosure relates to a device including a substrate, having a top surface and a bottom surface; an array of nanowires having a base and a top surface, the base contacting the top surface of the substrate; a contacting structure including the same material as the substrate having a non-nanostructured surface of a dimension suitable for forming an electrical contact, located on the same side of the substrate as the array of silicon nanowires; wherein the contacting structure is doped with a greater impurity concentration than the nanowire array, thereby forming a selective emitter.