Large thermoelectric power factor from crystal symmetry-protected non-bonding orbital in half-Heuslers.
Large thermoelectric power factor from crystal symmetry-protected non-bonding orbital in half-Heuslers.
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DOI：
10.1038/s41467-018-03866-w
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发表时间：
2018-04-30
影响因子：
16.6
通讯作者：
Chen G
中科院分区：
文献类型：
--
作者：
Zhou J;Zhu H;Liu TH;Song Q;He R;Mao J;Liu Z;Ren W;Liao B;Singh DJ;Ren Z;Chen G
现代社会依赖于高电荷流动性来实现高效的能源生产和快速的信息技术。材料的功率因数-电导率和塞贝克系数的组合-测量其从温差中提取电力的能力。热电材料的最新进展已经通过操纵电子能带结构实现了增强的塞贝克系数。然而，这种方法通常适用于相对较低的电导率，防止实现异常高的功率因数。相比之下，半赫斯勒半导体已经被证明可以以一种无法解释的方式突破这一障碍。在这里，我们表明，受保护的轨道相互作用可以引导电声声子相互作用向高流动性。这种高流动性制度使大功率因数的半赫斯勒，远高于最大测量值。我们预计，我们的理解将引发新的路线，以寻找更好的热电材料，并发现高电子迁移率半导体的电子和光子应用。在半赫斯勒合金中观察到的高功率因数的内在起源仍然难以捉摸，限制了新热电材料的设计。在这项工作中，作者揭示了这是由于削弱了电子-声学声子耦合，源于非键轨道的晶体对称性保护。
Modern society relies on high charge mobility for efficient energy production and fast information technologies. The power factor of a material—the combination of electrical conductivity and Seebeck coefficient—measures its ability to extract electrical power from temperature differences. Recent advancements in thermoelectric materials have achieved enhanced Seebeck coefficient by manipulating the electronic band structure. However, this approach generally applies at relatively low conductivities, preventing the realization of exceptionally high-power factors. In contrast, half-Heusler semiconductors have been shown to break through that barrier in a way that could not be explained. Here, we show that symmetry-protected orbital interactions can steer electron–acoustic phonon interactions towards high mobility. This high-mobility regime enables large power factors in half-Heuslers, well above the maximum measured values. We anticipate that our understanding will spark new routes to search for better thermoelectric materials, and to discover high electron mobility semiconductors for electronic and photonic applications. The intrinsic origin of high-power factors observed in half-Heusler alloys remains elusive, limiting the design of new thermoelectric materials. In this work, the authors reveal it is due to weakened electron–acoustic phonon coupling, originating from crystal symmetry protection of non-bonding orbitals.
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影响因子：
3.7
作者：
CARDONA, M;CHRISTENSEN, NE
通讯作者：
CHRISTENSEN, NE
影响因子：
8.6
作者：
Borisenko, Sergey;Gibson, Quinn;Cava, Robert J.
通讯作者：
Cava, Robert J.
影响因子：
64.8
作者：
Biswas, Kanishka;He, Jiaqing;Kanatzidis, Mercouri G.
通讯作者：
Kanatzidis, Mercouri G.
影响因子：
2.1
作者：
Ponnambalam, V.;Zhang, Bo;Poon, S. Joseph
通讯作者：
Poon, S. Joseph
稳定的三维拓扑狄拉克半金属Cd3As2
影响因子：
41.2
作者：
Liu, Z. K.;Jiang, J.;Chen, Y. L.
通讯作者：
Chen, Y. L.