ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 63, Number 3
JKCSEZ 63(3)
June 20, 2019 

The TADF properties for carbazol-dicyanobenzene, carbazol-diphenyl sulfone, carbazol-benzonitrile derivatives as OLED candidate materials are theoretically investigated using density functional theory (DFT) with 6-31G**, cc-pVDZ, and cc-pVTZ basis sets. The optimized geometries, harmonic vibrational frequencies, and HOMO-LUMO energy separations are predicted at the B3LYP/6-31G** level of theory. The harmonic vibrational frequencies of the molecules considered in this study show all real numbers implying true minima. The time dependent density functional theory (TD-DFT) calculations have been also applied to investigate the absorption and emission wavelength (λmax), energy differences (ΔEST) between excited singlet (S1) and triplet (T1) states of candidate materials.