TECHNOLOGY FOCUS - ELECTRONICS - Preferred Nanowires: In the array of nanowires, the distance is at least 300-525 mu m. Each of the set of nanowires includes a semiconductor material. The semiconductor material is silicon. Alternatively, the array of nanowires comprises: a set of nanowires, each of the set of nanowires including a first end at a first surface and a second end, the first end and the second end being separated by a first distance of at least 200 mu m; where: the set of nanowires corresponds to a first area on the first surface; and all nanowires of the set of nanowires are substantially parallel to each other. The set of nanowires is a part of a thermoelectric device. The first area is at least 100-5000 mm2 in size. Each of the set of nanostructures is substantially perpendicular to the first surface. Also, each of the set of nanowires corresponds to a cross-sectional area associated with a distance across, the distance across being less than 250 nm. The cross-sectional area is substantially uniform along a longitudinal direction for each of the set of nanowires. The set of nanowires includes a first nanowire and a second nanowire, the first nanowire and the second nanowire being separated by a second distance, the second distance being less than 1000 nm. Each of the set of nanowires is separated from another nanowire selected from the set of nanowires by a second distance, the second distance being less than 1000 nm. Each of the set of nanowires includes a semiconductor material. The semiconductor material is silicon. Preferred Nanostructures: In the array of nanostructures, the semiconductor material is silicon. The set of nanostructures corresponds to a set of nanoholes respectively. Alternatively, the array of nanostructures comprises: a set of nanostructures, each of the set of nanostructures including a first end at a first surface and a second end, the first end and the second end being separated by a first distance of at least 200 mu m; where: the set of nanostructures corresponds to a first area on the first surface; all nanostructures of the set of nanostructures are substantially parallel to each other; and each of the set of nanostructures includes a semiconductor material. Each of the set of nanostructures is substantially perpendicular to the first surface. Each of the set of nanoholes corresponds to a cross-sectional area associated with a distance across, the distance across being less than 250 nm. The cross-sectional area is substantially uniform along a longitudinal direction for each of the set of nanoholes. The set of nanostructures includes a first nanostructure and a second nanostructure, the first nanostructure and the second nanostructure being separated by a second distance, the second distance being less than 1000 nm. Each of the set of nanostructures is separated from another nanostructure selected from the set of nanostructures by a second distance, the second distance being less than 1000 nm. Preferred Method: In forming the array of nanowires, the semiconductor substrate includes silicon. The process for masking at least one or more portions of the one or more second surfaces includes applying one or more masking materials to the one or more second surfaces, where the one or more masking materials are selected from tape, nail polish, photo resist, silicon nitride (Si3N4), silicon carbide (SiC), diamond-like carbon (DLC), aluminum (Al), titanium (Ti), nickel (Ni), gold (Au), silver (Ag), chromium (Cr), indium titanium oxide (ITO), iron (Fe), platinum (Pt), and molybdenum (Mo). The metalized film includes one or more metals selected from a group consisting of Ag, Au, Pt, palladium (Pd), Ni, and copper (Cu). The first etchant solution includes one or more oxidizing agents, where the oxidizing agents are selected from silver nitrate (AgNO3), potassium nitrate (KNO3), sodium nitrate (NaNO3), iron nitrate (Fe(NO3)3), hydrogen peroxide (H2O2), silver chromate (Ag2CrO4), nitric acid (HNO3), and potassium manganate (KMnO4). The method further comprises etching the semiconductor substrate through at least the exposed portion of the first surface using a second etchant solution, the second etchant solution being different from the first etchant solution; washing the semiconductor substrate; after the process for forming a first set of nanowires, cleaning the semiconductor substrate; and after the process for forming a first set of nanowires, drying the semiconductor substrate. The semiconductor substrate includes a fourth surface opposite to the first surface; and the process for masking at least one or more portions of the one or more second surfaces includes keeping at least a second portion of the fourth surface exposed. The method as well comprises: applying the metalized film to at least the exposed second portion of the fourth surface; etching the semiconductor substrate through at least the exposed second portion of the fourth surface using the first etchant solution; and forming a second set of nanowires, each of the second set of nanowires including a third end at a fifth surface and a fourth end, the fifth surface being different from the third surface.