caa a22 4500 463233409 CHVBK 20180405153249.0 cr unu---uuuuu 170326e20070701xx s 000 0 eng 10.1007/s10853-006-0600-z doi (NATIONALLICENCE)springer-10.1007/s10853-006-0600-z Effect of the thickness of Bi-Te compound and Cu electrode on the resultant Seebeck coefficient in touching Cu/Bi-Te/Cu composites [Elektronische Daten] [Osamu Yamashita, Hirotaka Odahara] The resultant Seebeck coefficient α of the touching p- and n-type Cu/Bi-Te/Cu composites with different thicknesses of t Bi-Te and t Cu was measured as a function of t, where t Bi-Te was varied from 0.1 to 2.0mm, t Cu from 0.3 to 4.0mm and t is the lapse time after imposing the voltage. The temperature difference ΔT is produced by imposing a constant voltage of 1.70V on two Peltier modules connected in series. The resultant α of composites was calculated from the relation α=ΔV/ΔT, where ΔV and ΔT were measured with two probes placed on both end coppers. ΔV decreases abruptly with an increase of t below t=5min, while above t=7min, it tends to saturate to a constant value. The resultant α and saturated ΔV vary significantly with changes in t Cu and t Bi-Te. When a composite has a combination of t Cu=1.0mm and t Bi-Te=0.1mm, the generating powers ΔW (=(ΔV)2/4R) estimated using the saturated ΔV and calculated electrical resistance R for the p- and n-type composites have great local maximum values which are 4-5times as large as those obtained for the conventional combination of t Bi-Te=2.0mm and t Cu=0.3mm. It is surprising that the generating power ΔW is enhanced significantly by sandwiching a very thin Bi-Te material between two thick coppers, unlike the conventional composition of thermoelectric modules. On the other hand, when a composite has a combination of t Bi-Te=0.1mm and t Cu=0.3mm, the resultant α of the p- and n-type composites exhibited great values of 711 and −755μV/K, respectively, so that the maximum resultant ZT of the p- and n-type composites reached extremely large values of 8.81 and 5.99 at 298K. However, the resultant ZT decreases rapidly with an increase of t Cu or t Bi-Te. The resultant ZT is thus found to be enhanced significantly not only in superlattice systems but also in macroscopic composites. The present enhancement in ZT is attributed to the large barrier thermo-emf generated in the Bi-Te region shallower than 50μm from the boundary. Springer Science+Business Media, LLC, 2007 Yamashita Osamu Materials Science, Co., Ltd., 5-5-44, Minamikasugaoka, 567-0046, Ibaraki, Osaka, Japan aut Odahara Hirotaka Advanced Materials, Co., Ltd., 4-6-10, kizuri, 577-0827, Higashiosaka, Osaka, Japan aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/13(2007-07-01), 5057-5067 0022-2461 42:13<5057 2007 42 10853 https://doi.org/10.1007/s10853-006-0600-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-0600-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yamashita Osamu Materials Science, Co., Ltd., 5-5-44, Minamikasugaoka, 567-0046, Ibaraki, Osaka, Japan aut NATIONALLICENCE 700 1- Odahara Hirotaka Advanced Materials, Co., Ltd., 4-6-10, kizuri, 577-0827, Higashiosaka, Osaka, Japan aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/13(2007-07-01), 5057-5067 0022-2461 42:13<5057 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer