Thermoelectric Properties of In2O3(ZnO)k (k = 3, 4, 5, 7) Superlattice Ceramics.

In₂O₃(ZnO)_k superlattice ceramics are promising oxide thermoelectric materials, as superlattice interfaces are effective in scattering phonons and filtering low-energy electrons to decrease thermal conductivity and improve the figure of merit (ZT) value. In this work, homologous compounds were prepared by solid-state reaction method using ZnO and In₂O₃ as raw materials. Phase purity and crystal structure were characterized by x-ray diffraction, revealing that In₂O₃(ZnO)_k crystallizes in an R3 m space group for odd k values and P6₃/mmc for even k values. The study of thermoelectric (TE) properties showed that as k increased, the thickness of InO(ZnO)₃⁺ also increased, while the electrical conductivity, thermal conductivity, Seebeck coefficient, power factor and ZT value were all decreased. In₂O₃(ZnO)₃ samples obtained a maximum power factor of 651 μW m⁻¹ K⁻² at 973 K, and also achieved a maximum ZT value of 0.24 at 973 K. [ABSTRACT FROM AUTHOR]