(i) ELECTROTRANSPORT IN METALS
The effects of an applied electric field on diffusion in metals is
discussed. Frequently, under high current densities, and for
temperatures in the diffusion range, a directed displacement of the
diffusion species results. This mass transport is described by
the term electrotransport. The major theoretical considerations
relevant to the development of this topic are described, with particular
emphasis on derivations which have been applied to the interpretation
of experimental results. Previous experimental investigations
of electrotransport in metals are reviewed.The results of experiments on electrotransport of indium, using a
radioactive isotope technique, are presented. The investigations
are concerned with the electrotransport of the isotope In114m in
solid gold, thin gold films and thin indium films. Electrotransport
phenomena in thin films have not previously been investigated in any
detail. The results are amenable to interpretation in terms of the
interaction of electrons with an activated complex associated with
the diffusing species.(ii) ELECTROLUMINESCENCE IN ZINC TELLURIDE
This section reports on the electroluminescent properties of the
II VI semiconducting compound zinc telluride. Previous investigations
into the preparation of zinc telluride crystals and the optical,
electrical and electroluminescent properties of the material
are reviewed. The results of an experimental programme concerned
with the preparation of zinc telluride crystals and the electroluminescent
properties of devices fabricated from several forms
of the material are presented. Relatively simple contacting and
processing techniques are utilised and the electroluminescence is
primarily associated with metal :semiconductor junctions and contact
barrier regions. Particular emphasis is placed on the observation
of room- temperature electroluminescence in zinc telluride as this
has not been the subject of previous detailed investigation. The
incorporation of oxygen in the crystals results in radiative recombinations
in which temperature quenching of the emission is not pro-
nounced. This results in considerable improvement in room- tempera-
ture emission efficiencies; the associated emission is located in
the red region of the visible spectrum. Other forms of zinc
telluride investigated include nominally undoped and semi -insulating
single crystals and also polycrystalline material. The potential
of electroluminescent devices based on these various forms of zinc
telluride as room -temperature visible emitters is evaluated.
Possible mechanisms of electroluminescence are discussed
