  An unusual electron transfer phenomenon has been identified from an n-type
semiconductor to Schottky metal particles, the result of a unique metal
semiconductor interface that results when the metal particles are grown from
the semiconductor substrate. The unique interface acts as a one-way
(rectifying) open gateway and was first identified in reduced rutile
polycrystalline titanium dioxide (an n-type semiconductor) to Group VIII
(noble) metal particles. The interface significantly affects the Schottky
barrier height resulting in electron transfer to the metal particles from the
reduced rutile titanium dioxide (TiO2) based on their respective work
functions. The result is a negative charge on the metal particles which is of
sufficient magnitude and duration to provide cathodic protection of the metal
particles from surface oxidation.
