Conformation and Quantum-Interference-Enhanced Thermoelectric Properties of Diphenyl Diketopyrrolopyrrole Derivatives.
Conformation and Quantum-Interference-Enhanced Thermoelectric Properties of Diphenyl Diketopyrrolopyrrole Derivatives.
复制标题
DOI：
10.1021/acssensors.0c02043
复制
发表时间：
2021-02-26
期刊：
影响因子：
8.9
通讯作者：
Lambert C
中科院分区：
文献类型：
--
作者：
Almughathawi R;Hou S;Wu Q;Liu Z;Hong W;Lambert C
在单分子结中操纵外部电极与碳基分子中心环的连接是调节其热电性能的有效途径。在这里，我们利用密度泛函理论和紧束缚模型，结合量子输运理论，研究了一系列噻吩二酮吡咯(DPP)衍生物分子的热电性质与连接性的关系。我们发现电导与连接在DPP核上的两个噻吩环的连接性有很大的相关性。有趣的是，对于对应于构造性量子干涉(CQI)的连接性，通过旋转噻吩环得到的不同异构体具有相同的电导，而对应于破坏性量子干涉(DQI)的异构体在环旋转时表现出巨大的电导变化。此外，我们还发现DQI的连接性导致了塞贝克系数的增加，可以达到500-700μV/K。在计入声子对热导的贡献后，CQI分子的全优值系数(ZT)在室温下可以达到1.5，当温度升高到400K时，它将进一步增加到2。最后，我们证明了四氰基喹甲烷的掺杂可以通过与DPP形成电荷转移系统来改变塞贝克系数的符号。
Manipulating the connectivity of external electrodes to central rings of carbon-based molecules in single molecule junctions is an effective route to tune their thermoelectrical properties. Here we investigate the connectivity dependence of the thermoelectric properties of a series of thiophene-diketopyrrolopyrrole (DPP) derivative molecules using density functional theory and tight-binding modeling, combined with quantum transport theory. We find a significant dependence of electrical conductance on the connectivity of the two thiophene rings attached to the DPP core. Interestingly, for connectivities corresponding to constructive quantum interference (CQI), different isomers obtained by rotating the thiophene rings possess the same electrical conductance while those corresponding to destructive quantum interference (DQI) show huge conductance variations upon ring rotation. Furthermore, we find that DQI connectivity leads to enhanced Seebeck coefficients, which can reach 500–700 μV/K. After including the contribution to the thermal conductance from phonons, the full figure of merit (ZT) for the CQI molecules could reach 1.5 at room temperature and it would further increase to 2 when temperature elevates to 400 K. Finally, we demonstrate that doping with tetracyanoquinodimethane can change the sign of the Seebeck coefficients by forming a charge-transfer system with the DPP.
登录
查看更多内容
影响因子：
32.5
作者：
Bubnova, Olga;Crispin, Xavier
通讯作者：
Crispin, Xavier
影响因子：
64.8
作者：
Venkataraman, Latha;Klare, Jennifer E.;Steigerwald, Michael L.
通讯作者：
Steigerwald, Michael L.
影响因子：
29.4
作者：
Kronemeijer, Auke J.;Akkerman, Hylke B.;de Boer, Bert
通讯作者：
de Boer, Bert
影响因子：
3.3
作者：
Ferrer, J.;Lambert, C. J.;Algharagholy, L. A.
通讯作者：
Algharagholy, L. A.
影响因子：
4.3
作者：
Lambert, Colin J.;Liu, Shi-Xia
通讯作者：
Liu, Shi-Xia