NOVELTY - An apparatus (100) has a nanowire (102) grown from a surface of the non-single crystal substrate; and an electrode coupled to the nanowire. The nanowire is electrically conductive or optically active. The nanowire emits electromagnetic wave, or absorbs electromagnetic wave and generates a current.    USE - For use with display device (such as a flat panel display), radiation/light detector device, and/or a solar cell device.    ADVANTAGE - The apparatus is inexpensive to manufacture since it does not involve expensive materials (e.g., single crystalline silicon), and yet its nanowires retain the single crystalline properties for an efficient solar cell, radiation/light detector or light emitter. The nanowires combine the advantages (e.g., high photon-to-electron conversion efficiency) of single crystal semiconductor properties with non-single crystalline substrate. The growth time of nanowires can be short (e.g., approximately 30 seconds to a minute to grow an active region of approximately 1 microns).    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for fabricating the apparatus. The non-single crystal substrate comprises polycrystalline silicon, amorphous silicon, or microcrystalline silicon. The substrate includes a protruding portion consisting of polycrystalline silicon, amorphous silicon, polycrystal diamond and related carbon-based materials, or microcrystalline silicon. The non-single crystal substrate comprises glass, quartz, Mylar(RTM: thin polyester film), steel, metal, plastic, or stainless steel. The nanowire comprises metal, group III-V compound semiconductor material and related alloys, group II-VI compound semiconductor material and related alloys, or group IV semiconductor material and related alloys.    DESCRIPTION OF DRAWING(S) - The figure shows a side section view of an apparatus that includes one or more nanowires.    Apparatus (100)    Nanowire (102)    Non-single crystalline materials (104, 106)    Light (110)    Energy (112)