A number of configurations can be used to form p-n junctions in semico
nductors, by applying an electrical potential difference to them under
conditions where dopants, native or foreign, show ionic conductivity,
In all these cases the electrical potential difference guides the dop
ants to create compositional inhomogeneities. This can lead to actual
type conversion and thus to p-n junction formation, Junction formation
can be localized on a scale that is small compared to the sample size
, by working under conditions far from equilibrium and by limiting the
rmal effects.