Abstract: Self-assembled nanowires are provided, comprising nanowires of a first crystalline composition formed on a substrate of a second crystalline composition. The two crystalline materials are characterized by an asymmetric lattice mismatch, in which in the interfacial plane between the two materials, the first material has a close lattice match (in any direction) with the second material and has a large lattice mismatch in all other major crystallographic directions with the second material. This allows the unrestricted growth of the epitaxial crystal in the first direction, but limits the width in the other. The nanowires are grown by first selecting the appropriate combination of materials that fulfill the foregoing criteria. The surface of the substrate on which the nanowires are to be formed must be cleaned in order (1) to ensure that the surface has an atomically flat, regular atomic structure on terraces and regular steps and (2) to remove impurities.

Abstract: This method produces a field emitter material having a uniform electron emitting surface and a low turn-on voltage. Field emitter materials having uniform electron emitting surfaces as large as 1 square meter and turn-on voltages as low as 16V/.mu.m can be produced from films of electron emitting materials such as polycrystalline diamond, diamond-like carbon, graphite and amorphous carbon by the method of the present invention. The process involves conditioning the surface of a field emitter material by applying an electric field to the surface, preferably by scanning the surface of the field emitter material with an electrode maintained at a fixed distance of at least 3 .mu.m above the surface of the field emitter material and at a voltage of at least 500V. In order to enhance the uniformity of electron emission the step of conditioning can be preceeded by ion implanting carbon, nitrogen, argon, oxygen or hydrogen into the surface layers of the field emitter material.