Exploring the electronic structure of tetrathienylethene derivatives for OLED applications: A theoretical study

Abstract

The B3LYP/6-31G(d,p) method is applied to investigate the structural and electronic properties of tetrathienylethene (TTE) derivatives, specifically for the properties of 14 distinct TTE derivatives. The results indicate that the T1–T14 derivatives exhibit numerous advantages over the parent TTE compound. Notably, substituents predominantly impact the LUMO energy level of the TTE parent compound. Additionally, all modified molecules exhibit lower energy band gaps (Egap) and improved charge transfer capacity relative to TTE. These findings suggest that the T1–T14 derivatives may be promising candidates for use as materials in OLED applications. The values of chemical hardness (η) indicate that all compounds T1–T14 manifest greater softness relative to the parent compound TTE. This correlation aligns with the calculated Egap values, wherein compounds T1–T14 consistently exhibit smaller Egap values compared to the TTE compound. These research findings indicate that compounds T1 and T10 display remarkable and harmonious charge transfer capabilities. This is evident from their corresponding values of λh and λe, which stand at 0.39/0.41 and 0.41/0.41 eV, respectively. Remarkably, compound T1 exhibits the most pronounced absorption peak, occurring at a wavelength of 441 nm. This absorption is accompanied by the highest oscillator strength recorded for the compound, reaching a value of 0.638.