Effect of Ge substitution on carrier mobilities and thermoelectric properties of sintered p-type Ba8Ga16+xSn30－x－yGey with the type-VIII clathrate structure
Effect of Ge substitution on carrier mobilities and thermoelectric properties of sintered p-type Ba8Ga16+xSn30－x－yGey with the type-VIII clathrate structure
复制标题
Ge取代对VIII型笼形结构烧结p型Ba8Ga16+xSn30－x－yGey载流子迁移率和热电性能的影响
DOI：
10.1088/0022-3727/45/44/445306
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
K. Kishimoto
中科院分区：
文献类型：
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作者：
F. H. Latief;K. Kakehi;武藤寛明，戸高 孝，榎園正人;竹内健司;K. Kishimoto
为了改善Ba8Ga16Sn30的热电性能，尝试用Ge替代Sn.由于取代提高了熔点，因此可以提高烧结温度。烧结后的样品具有较高的热稳定性和较低的晶界陷阱态密度，这削弱了载流子的晶界散射。例如，Ba 8 Ga 16.4 Sn 25.0 Ge 4.6和Ba 8 Ga 16.9 Sn 19.8 Ge 9.3样品的室温迁移率分别为6.7 cm 2 V− 1 s− 1和13.3 cm 2 V− 1 s− 1，而Ba 8 Ga 16.6 Sn 29.4样品的室温迁移率为2.3 cm 2 V− 1 s− 1。因此，这些Ge取代的样品具有更高的优值系数的最大值0.62在550 K和0.63在600 K，分别比0.36在500 K的Ba 8 Ga 16.6 Sn 29.4样品。
Ge substitution for Sn in Ba 8 Ga 16 Sn 30 was attempted in order to improve its thermoelectric properties. Since the melting point was raised by the substitution, the sintering temperature could be increased. The resultant sintered samples exhibited higher thermal stabilities and fewer trapping state densities at grain boundaries, which weakened grain boundary scattering for carriers. For example, the Ba 8 Ga 16.4 Sn 25.0 Ge 4.6 and Ba 8 Ga 16.9 Sn 19.8 Ge 9.3 samples had larger room temperature mobilities of 6.7 cm 2 V− 1 s− 1 and 13.3 cm 2 V− 1 s− 1, respectively, than that of 2.3 cm 2 V− 1 s− 1 of the Ba 8 Ga 16.6 Sn 29.4 sample. Consequently, these Ge-substituted samples had higher figures-of-merit maxima of 0.62 at 550 K and 0.63 at 600 K, respectively, than that of 0.36 at 500 K for the Ba 8 Ga 16.6 Sn 29.4 sample.