Moreover, the impedance is extremely high, because the dominant electron conduction is difficult due to the least content of oxygen vacancies in the present W[O.sub.3] among all the W[O.sub.3-x] crystals.
Then the electron conduction becomes less dominant, while the contribution of electrolytic conduction will increase, causing the resistance of the W[O.sub.2.90] and [W.sub.19][O.sub.55] devices to increase first and then decrease.
Basically three types of conduction mechanism take place for extrinsically conductive composites above the room temperature; electric field radiation, hopping/tunneling of electrons, and electron conduction
through particle-particle contact [32, 33].
However, the small absorption overlap with the solar spectrum limits the photocurrent generation in fullerene acceptors, and their deep energy level for electron conduction
limits the open-circuit voltage.
(c) [R.sub.3] possibly originated from backward charge transfer from Ti[O.sub.2] to electrolyte and electron conduction
in porous Ti[O.sub.2] film.
From among the many ARPA studies, let me first single out research by Hans Frederikse's group on semiconductors based on d-electrons (as opposed to the more usual s-p electron conduction
This indicates the improved mass transportation and electron conduction
in the host materials.
Among them, the most common mechanism is based on the electron conduction
between the conductive filler particles by electron tunneling and hopping, when the interparticle distance is in the neighborhood of 100 [angstrom].