Theoretical investigation of the electro-optical properties of new II-conjugated molecules based on phenyl and pyrrole for organic light-emitting diodes (OLED) applications: a DFT approach

In the current research, five new π-conjugated compounds (Mi (i = 1–5)), based on terphenyl and pyrrole, were theoretically investigated to suggest novel organic materials that can be used in organic light-emitting diodes (OLEDs). The structural and electronic properties of designed compounds (Mi, i = 1–5) are evaluated using DFT/B3LYP/ 6-311G (d, p) quantum chemical method. Various parameters have been determined, including energy levels HOMO and LUMO, Eg, frontier molecular orbital (FMO), chemical reactivity descriptors, EA, IP, and λ (reorganization energy). TD−DFT/B3LYP/6–311G (d, p) approach has been applied to investigate a material's absorption and emission properties and the fluorescence lifetime. Hence, numerous properties of these compounds are determined, such as their λ_max (maximum wavelengths), E (vertical excitation energy), and related oscillator strengths. The calculated findings of the studied compounds Mi show that these molecules have suitable characteristics, which makes them promising candidates for OLED devices. Thus, this theoretical study of these molecules has been conducted to assist the experimental researchers in synthesizing them. These organic elements could potentially function as active components in OLED devices.