Thermoelectric (TE) materials can convert temperature differences into electricity directly and reversibly without air pollution, which provides a viable route for alleviating global warming and energy crisis. Here we use first-principles calculations combined with semi-classical Boltzmann transport theory to assess the potential of layered LaCuOSe for TE applications. Originating from the layered crystal structure, the electronic and thermal transport properties (i.e. Seebeck coefficient, electrical conductivity and thermal conductivity) are highly anisotropic between the in-plane and out-of-plane directions. The optimal figure of merit of 2.71 is achieved along the out-of-plane direction for electron doping at 900 K. Such excellent TE properties can be attributed to desired La-Se interlayer interaction between adjacent layers and relatively strong coupling between acoustic phonons and optical phonons, resulting in simultaneous enhancement of the electrical conductivity and suppression of the lattice thermal conductivity. This study provides a new route to improve the TE performance of layered LaCuOSe by utilizing anisotropic character of transport propereties and offers implications in promoting related experimental investigations. .

中文翻译：

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层状LaCuOSe：一种有前途的各向异性热电材料

热电（TE）材料可以将温度差异直接可逆地转换为电能，而不会污染空气，这为缓解全球变暖和能源危机提供了一条可行的途径。在这里，我们将第一性原理计算与半经典玻尔兹曼输运理论相结合，以评估分层LaCuOSe在TE应用中的潜力。源于层状晶体结构，电子和热传递性质（即塞贝克系数，电导率和热导率）在平面内和平面外方向上是高度各向异性的。沿面外方向在900 K时进行电子掺杂可获得2.71的最佳品质因数。如此优异的TE特性可以归因于相邻层之间的所需La-Se层间相互作用以及声子和光子之间的相对较强的耦合，从而导致电导率的同时提高和晶格热导率的抑制。这项研究提供了一种新的途径，通过利用运输特性的各向异性来提高LaCuOSe层的TE性能，并为促进相关的实验研究提供了启示。。这项研究提供了一种新的途径，通过利用运输特性的各向异性来提高LaCuOSe层的TE性能，并为促进相关的实验研究提供了启示。。这项研究提供了一种新的途径，通过利用运输特性的各向异性来提高LaCuOSe层的TE性能，并为促进相关的实验研究提供了启示。。