Publication Date:
2011-09-17
Description:
A unique micropore foaming technique was used to enhance the thermoelectric properties of polycrystalline aluminum-doped zinc oxide (AZO). Silicon carbide ( α-SiC ) and aluminum nitride (AlN) were used as foaming precursors. Thermoelectric conductivity, κ, decreased on addition of both precursors, increasing the porosity. Electric conductivity, σ, decreased upon addition of α-SiC , and subsequent addition of AlN reversed the effect. This phenomenon is due to the chemical reactions that occur upon addition of each precursor: the active oxidation of α-SiC and the decomposition reaction of AlN . The Seebeck coefficient, S , for 0.5 mol% AlN-doped AZO ( Al 0.005 Zn 0.995 O , AZO-0.005) was more than twice that of conventional non-doped AZO. Accordingly, the power factor and the figure of merit, ZT, for the porous AlN-doped AZO-0.005 were 4.9 and 5.8 times those of the conventional polycrystalline AZO, respectively, demonstrating that the compositionally optimized porous AZO exhibited excellent thermoelectric properties at high temperatures.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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