Ismael Ali K, Mohaymen Taha Taha Abdel, Al-Jobory Alaa
Department of Physics, Lancaster University, Lancaster LA1 4YB, UK.
Department of Physics, College of Education for Pure Science, Tikrit University, Tikrit, Iraq.
R Soc Open Sci. 2024 Jun 12;11(6):231734. doi: 10.1098/rsos.231734. eCollection 2024 Jun.
Tight-binding model (TBM) and density functional theory (DFT) calculations were employed. Both simulations have demonstrated that the electrical conductance for eight polycyclic aromatic hydrocarbons (PAHs) can be modulated by varying the number of aromatic rings (NAR) within the aromatic derivatives. TBM simulations reveal three distinct conductance states: low, medium and high for the studied PAH derivatives. The three distinct conductance states suggested by TBM are supported by DFT transmission curves, where the low conductance evidenced by () = 0, for benzene, naphthalene, pyrene and anthracene. While azulene and anthanthrene exhibit a medium conductance as () = 1, and tetracene and dibenzocoronene possess a high conductance with () = 2. Low, medium and high values were elucidated according to the energy gap and gaps are strongly dependent on the NAR in the PAH derivatives. This study also suggests that any PAH molecules are a conductor if < 0.20 eV. A linear relationship between the conductance and NAR (∝ NAR) was found and conductance follows the order (benzene, 1 NAR) < (anthanthrene, 4 NAR) < (dibenzocoronene, 9 NAR). The proposed study suggests a relevant step towards the practical application of molecular electronics and future device application.
采用了紧束缚模型（TBM）和密度泛函理论（DFT）计算。这两种模拟都表明，八种多环芳烃（PAHs）的电导率可以通过改变芳烃衍生物中的芳环数（NAR）来调节。TBM模拟揭示了所研究的PAH衍生物的三种不同的电导状态：低、中和高。TBM提出的三种不同的电导状态得到了DFT传输曲线的支持，其中苯、萘、芘和蒽的低电导由() = 0证明。而薁和蒽并蒽表现出中等电导，() = 1，四并苯和二苯并蔻具有高电导，() = 2。根据能隙阐明了低、中和高值，并且能隙强烈依赖于PAH衍生物中的NAR。该研究还表明，如果< 0.20 eV，任何PAH分子都是导体。发现了电导率与NAR之间的线性关系（∝ NAR），并且电导率遵循以下顺序：(苯，1个NAR) < (蒽并蒽，4个NAR) < (二苯并蔻，9个NAR)。所提出的研究表明了朝着分子电子学的实际应用和未来器件应用迈出的重要一步。
