Tunable spin electronic and thermoelectric properties in twisted triangulene π-dimer junctions
Tunable spin electronic and thermoelectric properties in twisted triangulene π-dimer junctions
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DOI：
10.1063/5.0056393
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发表时间：
2021-08
影响因子：
4
通讯作者：
Dan Wu;Lin Huang;Pin-Zhen Jia;Xuan-Hao Cao;Z. Fan;Wu-Xing Zhou;Keqiu Chen
中科院分区：
文献类型：
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作者：
Dan Wu;Lin Huang;Pin-Zhen Jia;Xuan-Hao Cao;Z. Fan;Wu-Xing Zhou;Keqiu Chen
在这项工作中，我们用第一性原理结合非平衡格林函数方法研究了扭角为0°~60°的三角烯π-二聚物结的电子性质和热电性能。研究发现，通过改变扭转角，三角烯π-二聚体可以在非磁态和反铁磁态或铁磁态之间转换。这是因为单体之间的相对旋转减弱了两个单占据分子轨道的重叠性。更重要的是，我们的理论分析表明，扭角为20°、30°和60°的三角烯π-二聚物结的铁磁态具有优异的热电性能。相应的ZT值高达6左右，这主要是由自旋分裂性质造成的。这项工作对改善π堆积分子结或有机聚合物的热电性能具有指导意义。
In this work, we investigate the electronic properties and thermoelectric performance of triangulene π-dimer junctions with the twist angle from 0° to 60° by using first-principles calculations in combination with a non-equilibrium Green's function method. It is found that the triangulene π-dimer can be transformed between nonmagnetic state and antiferromagnetic or ferromagnetic state by varying the twist angle. The reason is that the relative rotation between the monomers weakens the overlap of two single occupied molecular orbital. More importantly, our theoretical analysis shows that the ferromagnetic states of the triangulene π-dimer junctions at the twist angle of 20°, 30°, and 60° have outstanding thermoelectric performance. The corresponding ZT value is as high as around 6, which is mainly contributed from the spin splitting nature. This work is instructive to improve the thermoelectric properties of π-stacking molecular junctions or organic polymers.