  Electric field modulation analysis of thermopower (S) - carrier concentration
(n) relation of a bilayer laminate structure composed of a 1.5-nm thick
conducting layer, probably TinO2n-1 (n=2, 3,...) Magn\'eli phase, and rutile
TiO2 was performed. The results clearly showed that both the rutile TiO2 and
the thin interfacial layer contribute to carrier transport: the rutile TiO2
bulk region (mobility mu~0.03 cm2V-1s-1) and the 1.5-nm thick interfacial layer
(mu~0.3 cm2V-1s-1). The effective thickness of the interfacial layer, which was
obtained from the S-n relation, was below ~ 3 nm, which agrees well with that
of the TEM observation (~1.5 nm), clearly showing that electric field
modulation measurement of S-n relation can effectively clarify the carrier
transport properties of a bilayer laminate structure.
