Multifold Seebeck increase in RuO2 films by quantum-guided lanthanide dilute alloying

Abstract

Ab initio predictions indicating that alloying RuO2 with La, Eu, or Lu can increase the Seebeck coefficient α manifold due to quantum confinement effects are validated in sputter-deposited La-alloyed RuO2 films showing fourfold α increase. Combinatorial screening reveals that α enhancement correlates with La-induced lattice distortion, which also decreases the thermal conductivity twentyfold, conducive for high thermoelectric figures of merit. These insights should facilitate the rational design of high efficiency oxide-based thermoelectrics through quantum-guided alloying.

Temperature independent Seebeck coefficient through quantum confinement modulation in amorphous Nb-O/Ni-Ta-O multilayers

“…4. This specimen is an n-type thermoelectric exhibiting a relatively low electrical resistivity in the range of 20 μΩ m. In general, this low resistivity is unusual for oxides, such as Ta 2 O 5 being a common dielectric [50], since it is close to ordinary metals and well-known conductive oxides, such as RuO 2 [51,52] and In-Sn-O [53]. As this value is also lower than the resistivity of cubic NbO [9], this could be induced by metallic Ni reveled in the XPS (Fig.…”

“…3) assessments. Enhanced thermoelectric phases typically exhibit a pronounced and rather narrow peak in the electronic structure in the close vicinity of the Fermi level, which is known as quantum confinement [51,59,60]. In these Nb 50 O 50 /Ni 35 Ta 15 O 50 multilayers, there is no a very well defined peak, it is rather a broader region from the Fermi level to approx.…”

Critical evaluation of the colossal Seebeck coefficient of nanostructured rutile MnO2

“…Using equation ( 1) to obtain the Seebeck coefficient yields deviations up to 30% between measured and calculated values as many approximations are made, such as resonance scattering, phonon drag, anisotropy and size effects are ignored as well as constant relaxation time is assumed [3]. Nevertheless, considering ideal solids with band structure centred at the highest symmetry point (gamma point) still provides useful trends for experiments [3,[24][25][26][27][28][29].…”

Decreasing the Effective Thermal Conductivity in Glass Supported Thermoelectric Layers

“…This interpretation becomes especially important in case of thinner thermoelectric devices, where the initial heat gradient is often lost over time. [ 12 – 15 ]…”