Alotaibi Turki, Alshahrani Maryam, Alshammari Majed, Alotaibi Moteb, Taha Taha Abdel Mohaymen, Al-Jobory Alaa A, Ismael Ali
Department of Physics, College of Science, Jouf University, Sakaka 72388, Saudi Arabia.
Department of Physics, College of Science, University of Bisha, P.O. Box 551, Bisha 61922, Saudi Arabia.
ACS Omega. 2024 Jun 26;9(27):29537-29543. doi: 10.1021/acsomega.4c02141. eCollection 2024 Jul 9.
The orientational effect concept in a molecular-scale junction is established for asymmetric junctions, which requires the fulfillment of two conditions: (1) design of an asymmetric molecule with strong distinct terminal end groups and (2) construction of a doubly asymmetric junction by placing an asymmetric molecule in an asymmetric junction to form a multicomponent system such as Au/Zn-TPP+M/Au. Here, we demonstrate that molecular-scale junctions that satisfy the conditions of these effects can manifest Seebeck coefficients whose sign fluctuates depending on the orientation of the molecule within the asymmetric junction in a complete theoretical investigation. Three anthracene-based compounds are investigated in three different scenarios, one of which displays a bithermoelectric behavior due to the presence of strong anchor groups, including and . This bithermoelectricity demonstration implies that if molecules with alternating orientations can be placed between an asymmetric source and drain, they can be potentially utilized for increasing the thermovoltage in molecular-scale thermoelectric energy generators (TEGs).
分子尺度结中的取向效应概念是针对不对称结建立的，这需要满足两个条件：（1）设计具有强不同末端基团的不对称分子；（2）通过将不对称分子置于不对称结中以形成多组分体系（如Au/Zn-TPP+M/Au）来构建双重不对称结。在此，我们证明，在一项完整的理论研究中，满足这些效应条件的分子尺度结能够表现出塞贝克系数，其符号会根据分子在不对称结内的取向而波动。在三种不同情况下研究了三种基于蒽的化合物，其中一种由于存在包括 和 在内的强锚定基团而表现出双热电行为。这种双热电性的证明意味着，如果具有交替取向的分子能够置于不对称源极和漏极之间，那么它们有可能被用于提高分子尺度热电能量发生器（TEG）中的热电压。
