Theoretical design study on multifunctional triphenyl amino-based derivatives for OLEDs

摘要

The use of triphenyl amino-based derivatives in organic light-emitting diodes (OLEDs) can significantly improvetheir efficiency and stability and especially their electroluminescence characteristics - most of the new hole-transportmaterials have this feature. In this study, a series of triphenyl amino-based compounds were computed, including twonewly designed molecules. They can function as charge transport materials and emitters with high efficiency andstability. To reveal the relationship between the properties and structures of these bifunctional and multifunctionalelectroluminescent materials, the ground and excited state geometries were optimized at the B3LYP/6-31G(d), HF/6-31G(d), TD-B3LYP/6-31G(d), and CIS/6-31G(d) levels, respectively. The ionization potentials (IPs) and electronaffinities (EAs) were computed. The lowest excitation energies, the maximum absorption, and emission wavelengthsof these compounds were calculated by employing the time-dependent density functional theory (TD-DFT) method.Also, the mobilities of holes and electrons were studied computationally based on the Marcus electron transfer theory.The CH2Cl2 solvent effect on the absorption spectra of N,W-di-l-naphthyl-N,N'-diphenylbenzidine (NPB) was consideredby polarizable continuum model (PCM). The results obtained for these compounds are in good agreement with theexperimental values. These data show that the proposed compounds 1 and 2 (N,B-di-1-naphthyl-N,B-diphenylbenzidineand Mes2N[p-4,4'-biphenyl-NPh(1-naphthyl)]), are multifunctional and bifunctional materials similar to Mes2B[p-4,4'-biphenyl-NPh(1-naphthyl)] (BNPB) and NPB, respectively.