Thermoelectric properties of polycrystalline Si1-xGex grown by die-casting vertical Bridgman growth technique
Thermoelectric properties of polycrystalline Si1-xGex grown by die-casting vertical Bridgman growth technique
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DOI：
10.1557/proc-0886-f11-10
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发表时间：
2006-05
期刊：
影响因子：
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通讯作者：
Takashi Baba;T. Iida;Hisashi Hirahara;T. Itoh;M. Akasaka;Y. Takanashi
中科院分区：
文献类型：
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作者：
Takashi Baba;T. Iida;Hisashi Hirahara;T. Itoh;M. Akasaka;Y. Takanashi
压铸生长工艺结合布里奇曼法的先进版本被用于制造Si 1−x Ge x的多晶块状晶体。这一过程提供了一种与Si-Ge相图所预测的完全不同的相变形式。通过将这种生长与随后的沉淀样品的热处理相结合，对于载流子浓度在10 18 cm-3左右的Si 0.65 Ge 0.35样品，所获得的锗含量的变化在± 4%以内。在室温至800 K的温度范围内，功率因数呈现出相当平坦的特性。然而，在约800 K时塞贝克系数下降，这对应于电导率的上升。在600 ~ 900 K的温度范围内，热导率约为0.04 W/cm K。在773 K时，生长的Si 0.65Ge 0.35样品的优值最大，为0.19.
The die-casting growth process combined with an advanced version of the Bridgman method was employed for manufacturing the multicrystalline bulk crystal of Si 1−x Ge x . This process provides a form of phase transformation which is completely different from that predicted by the Si-Ge phase diagram. By combining this growth with subsequent heat treatment of the precipitated sample, the variation in the germanium content obtained was within ± 4 % for Si 0.65 Ge 0.35 sample with a carrier concentration in the mid-10 18 cm −3 . The power factor obtained exhibited a quite flat characteristic over the temperature range of room temperature to 800 K. However, there was a drop in the Seebeck coefficient at about 800 K, which corresponded to a rise in the electrical conductivity. The value of the thermal conductivity was about 0.04 W/cmK at temperatures ranging from 600 to 900 K. The maximum value of the figure of merit obtained for the grown Si 0.65 Ge 0.35 sample was 0.19 at 773 K.