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arXiv 1108.2109cond-mat.mtrl-sci
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n型热电材料PbSe的高温电荷和热输运性质

High temperature charge and thermal transport properties of the n-type thermoelectric material PbSe

John Androulakis, Duck-Young Chung, Xianli Su, Li Zhang, Ctirad Uher, Thomas C. Hassapis, Euripides Hatzikraniotis, Konstantinos M. Paraskevopoulos, Mercouri G. Kanatzidis

摘要:

本文详细研究了n型PbSe晶体的电荷输运、光学反射率和热输运性质。在500 K以上的温度下,一种强散射、迁移率限制机制被揭示出来。该机制是复杂的电子-声子相互作用,不能单独用传统的声学声子散射解释的指示。我们应用一阶非抛物近似提取了室温和700 K下态密度有效质量随掺杂的变化关系。结果进行了比较,抛物线带模型和掺杂依赖的红外光学反射率的研究。作为温度的函数的热导率行为显示出与预期的Debye-Peierls高温行为(umklapp为主)的强烈偏离,表明额外的载热通道,我们将其与光学声子激发相关联。的热导率观测的高温载流子迁移率行为的相关性进行了讨论。热电优值在700 K和1.5 x 10^{19}$ cm^-3时显示出约0.8的有希望值。

英文摘要:

We present a detailed study of the charge transport, optical reflectivity, and thermal transport properties of n-type PbSe crystals. A strong scattering, mobility-limiting mechanism was revealed to be at play at temperatures above 500 K. The mechanism is indicative of complex electron-phonon interactions that cannot be explained by conventional acoustical phonon scattering alone. We applied the first order non-parabolicity approximation to extract the density of states effective mass as a function of doping both at room temperature and at 700 K. The results are compared to those of a parabolic band model and in the light of doping dependent studies of the infrared optical reflectivity. The thermal conductivity behavior as a function of temperature shows strong deviation from the expected Debye-Peierls high temperature behavior (umklapp dominated) indicating an additional heat carrying channel, which we associate with optical phonon excitations. The correlation of the thermal conductivity observations to the high temperature carrier mobility behavior is discussed. The thermoelectric figure of merit exhibits a promising value of ~0.8 at 700K at 1.5 x 10^{19}$ cm^-3.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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