The present invention provides processes for producing horizontal nanowires that are separate and oriented and allow for processing directly on a substrate material. The nanowires grow horizontally by suppressing vertical growth from a nucleating particle, such as a metal film. The present invention also provides for horizontal nanowire growth from nucleating particles on the edges of nanometer-sized steps. Following processing, the nanowires can be removed from the substrate and transferred to other substrates. The present invention also provides for nanowires produced by these processes and electronic devices comprising these nanowires. The present invention also provides for nanowire growth apparatus that provide horizontal nanowires, and processes for producing nanowire devices.