A Theoretical Study On Charge Injection And Transport Properties Of Several Organic Light-emitting Molecules

The charge injection and transport properties of six organic light-emitting molecules with push-pull structures have been studied by theoretical calculations. It supports the result that has been obtained from the experiments and makes new prediction. The ground-state geometries in the neutral, cationic and anionic state were optimized using density functional theory. The ionization potentials and electron affinities were obtained. The reorganization energies and the transfer integrals were computed based on the Marcus electron transfer theory. According to the calculated ionization potential (IP), electron affinity (EA), reorganization energy (λ) and transfer integral (V), It was found that the six compounds are multifunctional materials being capable of transporting both holes and electrons in addition to being an emitter. Moreover, the double-branched compound of3-(dicyanomethylene)-5,5-dimethyl-1(4-diphenylamino-styryl) cyclohexene (DCDPC), namely DCDPC2, was found to have higher charge injection ability and better balanced charge transport properties than DCDPC do.