WEB Microstructural Design for Thermoelectricity: Interface modification in multiple scalesTuesday (22.09.2020) 11:35 - 11:50 Z: Special Symposia I Part of:
Thermoelectric (TE) power generation is considered to be one most promising emerging clean energy technologies for harvesting electricity from heat without producing any direct emission of greenhouse gases. The conversion efficiency of a TE material is quantified by a dimensionless quantity called the figure of merit, ZT = α2Tσ/κ Therefore, in order to have high-performance TE materials, an ideal combination of high electrical conductivity (σ) and Seebeck coefficient (α) and low thermal conductivity (κ) is required.
New approaches focusing on the role of the surfaces and the interfaces on transport properties open new ways to design materials with enhanced properties and new functionalities. Moreover, it is known that the electrical transport along grain boundaries and interfaces can be improved or depressed, even by several orders of magnitudes and various examples extensively studied are LaAlO3/SrTiO3 and La2CuO4-based interfaces[3,4], nanocrystalline ceria and mesoscopic SrTiO3. Therefore, microstructural design, particularly the utilization of the interfaces, can be critical for tailoring the thermoelectric functionality. From this point of view, we have investigated the electrical transport properties, Seebeck coefficient, and thermal conductivity of oxynitride (SiAlON), carbide (SiC), and oxide (SrTiO3, La2CuO4, LaNiO3) based materials by modifying interfaces in micro, nano, and atomic scales[7,8]. It is found that the segregated network approach can improve ZT unusually, decoration of grain boundaries tailored the electrical conductivity whilst multilayer approach is useful for tuning transport properties.
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