Tuning the Thermoelectric Properties of Transition Metal Oxide Thin Films and Superlattices on the Quantum Scale
Tuning the Thermoelectric Properties of Transition Metal Oxide Thin Films and Superlattices on the Quantum Scale
复制标题
在量子尺度上调节过渡金属氧化物薄膜和超晶格的热电性能
DOI：
10.1002/pssb.202100270
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
R. Pentcheva
中科院分区：
文献类型：
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作者：
B. Geisler;P. Yordanov;M. Gruner;B. Keimer;R. Pentcheva
在密度泛函理论和玻尔兹曼输运理论的框架下，将先进的生长和表征技术与最新的第一性原理模拟相结合，讨论了作为热电材料的过渡金属氧化物薄膜和超晶格(SLS)领域的最新进展，特别是选择了一种量子尺度的方法来调整它们的热电性能。特别是，在规则衬底和错切衬底上生长的PdCoO2薄膜使得实验上证实了这种各向异性材料的大的平面外Seebeck系数，并揭示了Co3d态的Hubbard-U参数的必要性。此外，氧的扩散和掺杂使LaNiO3/LaAlO3(001)SLS的高温Seebeck系数显著提高。然后，利用LaNiO3/SrTiO3(0 0 1)SL中的界面极性，或利用外延应变使(LaNi3)3/(LaAlO3)1(0 0 1)SLS中与轨道有关的输运共振跨费米能级移动，从而获得n型和p型材料。此外，在短周期(LaNiO_3)_1/(LaAlO_3)_1(001)和(SrX_2O_3)_1/(SrTiO_3)_1(001)SLS(X=V，Cr，Mn)中，约束和应变诱导的金属-绝缘体相变导致了较高的Seebeck系数和功率因数。最后，建立了(EuO)1/(MgO)3(001)SLS中拓扑非平凡的陈氏绝缘行为与增强的热电响应之间的关系。文章最后讨论了氧化物热电材料面临的挑战和未来的研究课题。
Combining advanced growth and characterization techniques with state‐of‐the‐art first‐principles simulations in the frameworks of density functional theory and Boltzmann transport theory, recent advances in the field of transition metal oxide films and superlattices (SLs) as thermoelectric materials are discussed, with particular focus on a selection of quantum‐scale approaches to tune their thermoelectric performance. Specifically, PdCoO 2 films grown on regular and miscut substrates have enabled experimental confirmation of the large predicted out‐of‐plane Seebeck coefficient of this anisotropic material and also reveal the necessity of a Hubbard‐U parameter on the Co 3 d states. Furthermore, oxygen diffusion and incorporation from the SrTiO 3 ( 001 ) substrate lead to a significant enhancement of the high‐temperature Seebeck coefficient in LaNiO 3 / LaAlO 3 ( 001 ) SLs. Next, it is shown how n‐ and p‐type materials can be achieved either by exploiting interface polarity in a LaNiO 3 / SrTiO 3 ( 001 ) SL or using epitaxial strain to shift orbital‐dependent transport resonances across the Fermi level in ( LaNiO 3 ) 3 / ( LaAlO 3 ) 1 ( 001 ) SLs. Moreover, confinement‐ and strain‐induced metal‐to‐insulator transitions induce high Seebeck coefficients and power factors in short‐period ( LaNiO 3 ) 1 / ( LaAlO 3 ) 1 ( 001 ) and ( Sr X O 3 ) 1 / ( SrTiO 3 ) 1 ( 001 ) SLs ( X = V, Cr, Mn). Finally, a relation between the topologically nontrivial Chern insulating behavior and enhanced thermoelectric response in ( EuO) 1 / ( MgO) 3 ( 001 ) SLs is established. The article concludes with a discussion of challenges and future topics of research in oxide thermoelectrics.