Electronically excited states of carbazole-modified ortho-phenylenes

In recent years new materials for phosphorescent organic light-emitting diodes were found from complexes of carbazole-modified ortho-phenylene derivatives. We investigate theoretically the photo-induced charge transfer in these complexes. The electronically excited states and absorption spectra of tetramer ortho-phenylene (OP) derivatives were first studied by using time-dependent density functional theory calculations with various functionals. The functional that best reproduced the experimental results was found to be omega B97XD, and the assignment of the experimentally observed ultraviolet-visible absorption spectrum was successfully performed in comparison with the theoretically obtained one. We then performed a spectral assignment of carbazole-modified OP derivatives. (C) 2017 Elsevier B.V. All rights reserved.