Electric field thermopower modulation analysis of an interfacial conducting layer formed between Y₂O₃ and rutile TiO₂

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 Ti_nO_2n-1 (n = 2, 3,√ ) Magnéli 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 μ ∼ 0.03 cm² V^-1 s^-1) and the 1.5-nm-thick interfacial layer (μ ∼ 0.3 cm² V^-1 s^-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.