NOVELTY - A nano-whisker column includes two lengthwise segments of different crystalline materials along its length. The diameter of the column allows lattice strain caused by lattice mismatch at the composition boundary to be accommodated by lateral outward atomic displacement. The composition boundary between crystalline materials of two portions extends over an axial interval of at most eight diametral lattice planes.    USE - For use in resonant tunneling diode, hetero-bipolar transistor, single photon light source, light emitting diode, photodetector, solar cell, source of terahertz radiation, field emission display, phosphor display screen, display system, antenna for infrared or visible or ultraviolet electromagnetic radiation, electrode structure, and photonic crystal (claimed).    ADVANTAGE - The invention provides improved or precise electrical characteristics than nano-whiskers with exposed conductive material along their lengths.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) photoresist layer patterning apparatus in a nano-imprint lithography process comprising a carriage moveable over a photoresist surface and carrying a light emitting diode array. Each light emitting diode of array comprises a one-dimensional nano-element having disposed along its length a volume of optically active material small to form a quantum well. The well has tunneling barriers formed on either side of the quantum well. The nano-elements are side by side but selectively energizable to produce a pattern in photoresist surface;    (2) forming a photonic crystal comprising forming on a substrate surface an array of seed particle forming areas, and employing seed particles to grow nano-whiskers extending upright from the substrate. The nano-whisker has a constant diameter of a dimension to provide a photonic band gap for incident electromagnetic radiation;    (3) forming an epitaxial layer of a second crystalline material on a substrate of a first crystalline material different from second crystalline material comprising forming on a surface of the substrate seed particle material areas; forming a layer of mask material around the seed particle material areas; growing nano-whiskers of second crystalline material from the seed particle material areas; and continuing to grow second crystalline material using the nano-whiskers as growth sites to create an epitaxial layer of second crystalline material extending over the substrate;    (4) a layered structure comprising a crystalline substrate containing first crystalline material; a layer of mask material covering a surface of crystalline substrate, layer of mask material capable of inhibiting epitaxial growth on surface of crystalline substrate, and has an array of apertures of nanometer dimension exposing within apertures epitaxial growth sites on surface of crystalline substrate; and an epitaxial layer of a second crystalline material grown from epitaxial growth sites on surface of crystalline substrate; and    (5) array comprising nano-whiskers extending parallel to one another.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic depiction of fabrication technique for forming nano-whiskers deposition of size-selected gold aerosol particles on a gallium-arsenic substrate.