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Defect and Dopant Mediated Thermoelectric Power Factor Tuning in β‐Zn4Sb3
Advanced Electronic Materials ( IF 5.3 ) Pub Date : 2020-02-13 , DOI: 10.1002/aelm.201901284
Vaithinathan Karthikeyan 1 , Tan Li 1 , Bharat Medasani 2 , Caiqin Luo 3 , Dongliang Shi 4 , Joseph C. K. Wong 5 , Kwok‐Ho Lam 4 , Francis C. C. Ling 3 , Vellaisamy A. L. Roy 6
Affiliation  

The presence of defects in thermoelectric materials plays a significant role in the modification their properties by influencing the behavior of electrons and phonons. Dopants with a unique f‐orbital can directly cause distortions in electronic density of states (eDOS) and phonon transport mechanism by intentionally inducing defects in their lattice. The theoretical and experimental outcomes of engineered vacancy defects are investigated by intentional doping of f‐block rare earth elements in β‐Zn4Sb3. Thermoelectric behavior breaks down the inverse relation and results in a parallel increase in Seebeck coefficient and electrical conductivity for β‐(Zn0.997Ce0.003)4Sb3 and β‐(Zn0.997Er0.003)4Sb3. This synergistic response triples the power factor of a thermoelectric β‐Zn4Sb3 system realized by the impurity induced resonant distortion in eDOS. From first principle GGA + U calculations, the above‐mentioned unconventional properties are attributed to the effect of doping induced vacancy formation and the formation of resonant impurity levels. Hence, it is postulated that defect engineering can be a broad strategy to improve the power factor of the system and can be extended to other thermoelectric materials.

中文翻译:

β-Zn4Sb3中的缺陷和掺杂剂介导的热电功率因数调谐

通过影响电子和声子的行为,热电材料中缺陷的存在在改变其性能方面起着重要作用。具有特有f轨道的掺杂剂可以通过故意在晶格中引起缺陷,从而直接导致电子态密度(eDOS)和声子传输机制的畸变。工程改造的空位缺陷的理论和实验结果是由f区稀土元素掺杂故意在β-Zn系研究4的Sb 3。β-(Zn 0.997 Ce 0.0034 Sb 3和β-(Zn )的热电行为打破了逆关系,并导致塞贝克系数和电导率平行增加0.997 Er 0.0034 Sb 3。这种协同响应三倍的热电β-Zn系的功率因数4的Sb 3通过在EDOS诱导谐振失真的杂质来实现系统。从第一原理GGA + U计算得出,上述非常规特性归因于掺杂引起的空位形成和共振杂质能级的形成。因此,假设缺陷工程可以是提高系统功率因数的广泛策略,并且可以扩展到其他热电材料。
更新日期:2020-02-13
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