One embodiment includes noncatalytically forming a nanowire on a substrate from an organometallic vapor without application of any type of reduction agent. The nanowire is grown during this formation in a direction away from the substrate and is freestanding during growth. The nanowire has a first dimension of 500 nanometers or less and a second dimension extending from the substrate to a free end of the nanowire at least 10 times greater than the first dimension. In one form, the organometallic vapor includes copper and the nanowire essentially consists of elemental copper, a copper alloy, or oxide of copper. Alternatively or additionally, the nanowire is of a monocrystalline structure.