Jothi B, Stephen A David, Selvaraju K, Al-Sehemi Abdullah G
Department of Physics, Kandaswami Kandar's College, Velur, Tamilnadu, India.
Department of Physics, PSG College of Arts & Science, Coimbatore, Tamilnadu, India.
Heliyon. 2023 May 26;9(6):e16740. doi: 10.1016/j.heliyon.2023.e16740. eCollection 2023 Jun.
The effects of substituting electron withdrawing and electron donating functional groups on the electronic and optical properties of angular naphthodithiophene (aNDT) were studied. Substitutions were made to the aNDT molecule at position 2 and 7, respectively. The computed ionization parameters and reorganisation energies distinguished between the p-type and n-type semiconducting natures of the unsubstituted aNDT molecule and those with the -CH, -OCH, -NO, and -CN substituents. However, the aNDT molecule with CH as a substitution showed p-type behaviour since it had the largest electron reorganisation energy of about 0.37 eV. The ambipolar semiconducting property of methoxy [-OCH-] substituted aNDT molecule was revealed from the RMSD value of 0.03 Å for both positive and negative charges with respect to neutral geometry. The absorption spectra differ significantly from those of unsubstituted aNDT, which reveals the impact of functional group substitution that changes the energy level of the molecules. The maximum absorption () and oscillator strength (f) at the excited states in vacuum was investigated using time dependent density functional theory (TD-DFT). The aNDT with electron withdrawing group [-NO] substitution has a maximum absorption wavelength of 408 nm. Studying the intermolecular interactions between aNDT molecules was also accomplished with the help of Hirshfeld surface analysis. The current work provides insight into the development of novel organic semiconductors.
研究了在角萘并二噻吩（aNDT）的2位和7位分别取代吸电子和给电子官能团对其电子和光学性质的影响。计算得到的电离参数和重组能区分了未取代的aNDT分子以及带有-CH、-OCH、-NO和-CN取代基的aNDT分子的p型和n型半导体性质。然而，以-CH为取代基的aNDT分子表现出p型行为，因为它具有约0.37 eV的最大电子重组能。甲氧基[-OCH-]取代的aNDT分子的双极性半导体性质是通过相对于中性几何结构的正负电荷均方根偏差（RMSD）值为0.03 Å揭示的。吸收光谱与未取代的aNDT有显著差异，这揭示了官能团取代对分子能级的影响。利用含时密度泛函理论（TD-DFT）研究了真空中激发态的最大吸收（）和振子强度（f）。带有吸电子基团[-NO]取代的aNDT的最大吸收波长为408 nm。借助Hirshfeld表面分析也完成了对aNDT分子间相互作用的研究。目前的工作为新型有机半导体的开发提供了见解。
