Patent ID: 8568877

Claim:
A method of making a porous nanowire or nanowire-like structure comprising: obtaining an etchable substrate; performing metal-assisted electroless etch comprising the steps of: (i) forming on a surface of the substrate a patterned porosification assisting metal layer that has at least one opening, wherein said opening has at least one lateral dimension of no more than 5 microns; and (ii) exposing the substrate to an etching solution, wherein said etching solution dissolves the patterned porosification assisting layer to form a metal containing etching solution, and wherein the metal containing etching solution etches a first portion of the substrate to form an elongated structure, and porosifies a portion of the elongated structure to form a nanoporous nanowire or nanowire-like structure having a cross-section determined by the opening, wherein the cross-section is substantially perpendicular to the axis, the cross-section has at least one lateral dimension of no more than 5 microns, and said porous nanowire or nanowire-like structure has an aspect ratio no less than 4.