Electronic pathway of the exciplex emitters. Unraveling the emission properties from theoretical calculations

Abstract

Most emissive materials have become significant research findings for building organic light-emitting diode (OLED) devices. Prominent organic electronics reach applications such as displays, lighting, and photodynamic therapy, among others. Thus, the area of organic emitters has rapidly developed thanks to the synergy between theoretical and experimental works. Here, organic emitters are accurately studied, describing their electronic structure, including the electronic transitions, excited state energies, and coupling characteristics. Consequently, a tandem of methodologies, such as density functional theory (DFT) and time-dependent density functional theory (TDDFT), besides the MD-ReaxFF simulations, were employed. Therefore, we focus on exciplex emitters reported as donating-accepting to describe the photophysical process contained in such emitters, establishing electron hopping rates from the monomer and dimeric conformations and assessing the singlet and triplet states. The evaluations of electronic coupling and the reorganization energy (λ) enable the accurate computing of crossing hopping for dimer and free dyes, proposing a reliable scheme of charge transfer properties. These findings bear a novel strategy for studying OLED devices and pave the way for developing more environmentally friendly technologies.