Drastic improvement of oxide thermoelectric performance using thermal and plasma treatments of the InGaZnO thin films grown by sputtering

作者：Seo Dong Kyu; Shin Sangwoo; Cho Hyung Hee; Kong Bo Hyun; Whang Dong Mok; Cho Hyung Koun^*

来源：Acta Materialia, 2011, 59(17): 6743-6750.

DOI：10.1016/j.actamat.2011.07.032

• Thermoelectric
• InGaO3(ZnO)(m)
• Superlattice
• Plasma treatment

Single-crystal InGaO3(ZnO)(m) thin films with periodic superlattice structures suitable for transparent thermoelectric applications were fabricated using a commercially available c-plane sapphire substrate, an epitaxial ZnO buffer layer, a thermal treatment at 900 degrees C, and an Ar plasma treatment. The introduction of the cpitaxial ZnO buffer layer led to a significant reduction in the lattice mismatch at the interface with the InGaO3(ZnO)(m) films. The sandwich structure of the ZnO/InGaZnO/ZnO resulted in an increase in the ZnO content in the superlattice InGaO3(ZnO)(m) thin films. With respect to thermoelectric properties, the formation of a perfect, layered structure induced an increase in the Seebeck coefficient and, at the same time, a decrease in the thermal conductivity. After complete crystallization, the Ar plasma treatment resulted in a considerable decrease in the electrical resistivity without microstructural changes and without a large decrease in the thermal conductivity. As a result, the thermoelectric properties using n-type oxide semiconductors were dramatically improved.

• 出版日期2011-10