Theoretical Study on Photophysical Properties of Ambipolar Spirobifluorene Derivatives as Efficient Blue-Light-Emitting Materials

Abstract

The aim of this work is to provide an in-depth interpretation of the optical and electronic properties of a series of spirobifluorene derivatives. These materials show great potential for application in organic light-emitting diodes as efficient blue-light-emitting materials due to the tuning of the optical and electronic properties by the use of different electron donors (D) and electron acceptors (A). The geometric and electronic structures of the molecules in the ground state are studied with density functional theory (DFT) and ab initio HF, whereas the lowest singlet excited states are optimized by ab initio CIS. The energies of the lowest singlet excited states are calculated by employing time-dependent density functional theory (TD-DFT). The results show that the HOMOs, LUMOs, energy gaps, ionization potentials, electron affinities, reorganization energies, and exciton binding energies for these complexes are affected by different D and A moieties. Also, it has obtained that these blue-light-emitting materials have improved charge transport rate and charge transfer balance performance and can be used as efficient ambipolar-transporting materials in organic light-emitting diodes.

Theoretical investigation of the static (hyper)polarizabilities and reorganization energy of 4,5-dicyanoimidazole chromophore and derivatives containing benzene rings and a saturated bridge

“…Therefore, to compare the transport properties of the investigated molecules, we calculated the reorganization energies for each structure, based on Eqs. (7) and (8). The results are summarized in Table 3.…”

“…Specifically, the electron-phonon coupling can be address from the so called reorganization energy (k) [7]. In fact, the lower the reorganization energy value is, the higher the charge transfer rate [8]. On the other hand, third-order nonlinear optical (NLO) properties of organic systems also have potential applications in optoelectronic devices [6][7][8][9].…”

“…In fact, the lower the reorganization energy value is, the higher the charge transfer rate [8]. On the other hand, third-order nonlinear optical (NLO) properties of organic systems also have potential applications in optoelectronic devices [6][7][8][9]. The behavior of these NLO properties in organic compounds is associated to the electronic delocalization of the isolated molecule.…”

Photophysical and Electroluminescence Properties of Some 2-(5,6-Dihydrobenzimidazo[1,2-c]quinazolin-6-yl)-5-substituted Phenol Schiff Bases Derivatives toward Organic Light Emitting Diodes: DFT Study

“…The reorganization energy is inversely related to the charge transfer rate [21,22] and L-OCH3 are about 50 % smaller than that of tris(8-hydroxyquinolinato)aluminum(III) (Alq3), which is a good electron transport material with λe = 0.276 eV [24]. This suggests that our studied compounds electron transfer rates might be higher than that of The L-H molecule was successfully optimized in the ±X, ±Y and ±Z direction under applied uniform current field of 3.0 V/Å.…”

Theoretical study of the optical, electronic, and charge-transfer properties of 1,2,4,5-tetrakis(phenylethynyl)benzene derivatives for solar cell applications

“…Here, the reorganization energies are the internal reorganization energies of the isolated active organic -conjugated system, ignoring any environmental relaxation and changes. The lower the reorganization energy, the higher the charge transfer rate [29]. To compare the charge-transport properties of the investigated molecules, we calculated the reorganization energies associated with the different geometries of two states (anion and cation) based on Equations (2) and (3).…”